Attempts stall, Idle Pulses 600-800 rpms, horrible MPG

Raw fuel leaking out the exhaust manifold - exhaust y-pipe connection....

Ran the engine for 20 to 30 secs...

Spark plug gaps....

If you've really got copious amounts of raw fuel leaking (blowing?) out that connection, a spark plug gap that's within a factor of two of the spec isn't very likely to cause this. Twenty to thirty seconds is not very long to fill up a whole exhaust pipe (or even one cylinder for that matter), so the leak you're looking at sounds to be large.

If an injector was leaking continuously (or more than one), then it could result in much more fuel than something that's only happening while the engine is running. An injector could be stuck open either mechanically or electrically. As mentioned, one wire of each injector is connected to VPWR at all times, and the PCM grounds the other (through a transistor in the PCM) for a length of time according to the amount of fuel that is needed. Most of the time this wire is not grounded, so a normal voltmeter will read only a small voltage (maybe a few 0.1 volts) across the wires (not to ground). I used an oscilloscope recently to look at these voltages on my Windstar and was able to observe the voltage waveform. I also tried a DVM on it, but it recorded only a small voltage.

I also checked my injectors for leaks without using any special equipment. I pulled them out of the lower intake manifold, leaving them on the fuel rails which was still connected to the fuel lines and disconnected wire to each injector, then I turned the on the key to get fuel pressure. Looking at each injector I could see that none were leaking. I also checked each one for operation (being very careful since highly flamable fuel and electrical sparks are involved here) by applying 12 volts from the battery to the terminals of each injector. I let the spray from each injector blow into a clear glass jar so that I could see the volume and pattern of the spray. I didn't do this, but you could also connect the PCM wires to each injector and make sure that there are no leaks with the key off and with the key on.

A quick test to see if you have a injector physically leaking is to turn the key to the ON position, but don't crank the motor.
This will bring the fuel system up to pressure.
Then turn the key OFF.
After a few minutes, check for fuel pressure at the fuel rail.
If you have fuel pressure, not dropping significantly.....then you don't have a big leakage.
If it drops significantly, then you have a leak.

To check if a injector is leaking with Key ON, motor OFF, you could do the same test, but remove the fuse for the fuel pump after the fuel pressure is up.....
Then, leaving the Key ON, motor OFF.......check the fuel pressure after a few minutes to see if it drops significantly.

These checks would see if you have a mechanical leakage (on new injectors, I hope not, but worth checking....maybe a dirt particle on the internal injector valve seat) or a electrical activation of a injector.
It sure is a faster check than trying to measure voltages at each injector.

The spark check (using a timing light) that I mentioned is to see if you have a dead cylinder as far as spark goes.....you know you have spark to some cylinders......as the motor runs (somewhat). No spark to a cylinder will send raw fuel into the exhaust.
There is a spark to each cylinder 2 times in each cycle......1 spark is wasted, during the exhaust stroke.....which I would expect would still ignite the air/fuel mixture.....(backfire?)......the other spark is the one that ignites....and causes the motor to run as it should.

I do remember all the fuss that you went through getting the correct fuel injectors......so I would expect that they are the correct ones.

Sorry I don't have more to offer.....I am not a mechanic.....just trying to think through this along with you.

Today's News:
Replaced all plugs with properly gapped plugs. I became a circus contortion act to do it too.... that is without removing the intake plenum... i just removed the center air pipe piece and pushed my big body to the limits. #1 spark plug was the hardest and I was able to squeeze my left arm down there over the coils to get at it.

The spec is .054" and all the plugs I removed today were between .039" and .046" randomly all different. I don't know what you meant by "factor of 2", but to me thats just stupid for them to have installed them that way and from what i know should cause engine running problems. All plugs were coated charred black and smelled of fuel..... every one. I'm gonna get some pictures up tonight or tomorrow.

I'm not for a moment suggesting that fuel spewing out the ypipe connection is from mis gapped burnt spark plugs, but I was hoping that the plugs were in such bad shape that the fuel coming out was because they weren't getting burned.

Status after plugs replaced: Fuel still spitting out the ypipe connection point, van still acting like its misfiring, though it is not running "as bad" now. I would like to explore this further with you guys so lets keep up discussion, but I have called my insurance company to have it towed to the offending shop tomorrow.

I ran it for about 15 - 20 seconds and the puddle that came out was about 3 inches wide on the ground; not a thick/deep puddle, but spread out evenly on the pavement.

At this point I'm not sure if the PCM was fried and is sending constant fuel injector WOT signals (guessing at that) or what the deal is.

I have not tested the plug wires with the timing light. Perhaps one or more of them is bad. I don't know what else to say at this point. The performance coils should be working fine. They resistance tested fine, but even if they weren't it wouldn't cause gas to constantly spit out into the exhaust.

Since my injectors are new, I would bet the issue is electrically stuck open. I just don't know why because I can't run the engine long enough to hopefully get a code to pop up.

I don't believe any injector is "leaking" per say, but is more likely being held open by voltage. I guess tomorrow I can check pressure though before I send the van off.

THAT SUGGESTION FOR REMOVING THE FUSE FOR THE FUEL PUMP and checking for sharp drops in the fuel pressure is BRILLIANT !!!!! WHY DIDN'T I THINK OF THAT !!!! LOL - I'll try that too tomorrow before the tow if I have time to before they get here.

I really do not want to remove the intake again. It would be easier to do it again though since I've been through it now, but I really don't want to. In order to do all those injector tests thats what I'd have to do and I don't have the patience for it right now since I spent 5 days putting it back together all nice'n spec.

Is there a SAFE way to bench test spark plugs out of the engine?

If I use the timing light to determine if I'm getting spark to the plugs via the plug wires how safe is that? Could the spark jump to me or some other part of the van during testing?

Brief thoughts that would cause this?
1. Fried PCM?

2. Improperly grounded injector harness wiring (somehow due to wires having previously melted together) or charred wiring.. no good anymore.

3. O2 sensor's no good?? Could an O2 sensor poisoned to death by fuel cause an overly continuous rich condition?

4. TPS gone bad?? Could the TPS be just not functioning at all or sending WOT signals causing all this rush of excessive fuel? TPS is the original. I have a new one I bought a long time ago, but never put it in cause I didn't want to mess up the setting. I guess I should have just tried this by now.

No sorries from anyone. :) Ya'll give me wonderful ideas that are thought of differently than I'd think to try. Keep it coming and tell me what ya'll think of my 1 - 4 ideas.:ylsuper::ylsuper::ylsuper: You guys rock! I Love you guys! lol :ylsuper::ylsuper::ylsuper:

#5 - Forgot to mention, Ignition Control Module - Maybe a long shot, but maybe not. I haven't checked voltage to this connector either. Always meant to, but I figured if this was bad that I'd get a code.......yet again.... engine not running long enough to get a code.

I went by the shop today with the old plugs and showed'em. They said I'm running extremely rich on all cylinders, but are seeming to focus on the front bank since I can literally see fuel coming out. I told'em for all I know fuel is coming out the back bank too, but I just don't see it on the ground.

Towing it over there Monday morning. I was extremely worn out and tired from all the work on the plugs yesterday and overslept so I figure getting it to them at the start of the week is more preferred anyway as they confirmed when I went over there.

Gonna perform a few small easy tests this weekend since I still have it. Gonna do the ones ya'll suggest and I just realized that I have a spark plug tester that I've never opened. lol - I have cool things I didn't even know about. It hooks up "flush" between the wire and plug with a light in between, so that'll prove very useful - I HOPE.

"Grounding" the fuel injector harness......
Think of the injector firing in terms of the only electrical connections......a constant +12Volts....and a momentary ground......provided by the PCM.
The only ground should be the ground that the PCM provides to that 1 wire per injector.
I would do the fuel pressure test......Key ON.....pump runs to provide fuel pressure......remove fuel pump fuse (as our older windstars have the fuel pump relay inside the CCRM unit)......and monitor fuel pressure.
This pressure drop should be major......to be providing all that fuel out the exhaust.
Remember....1 gallon is good for a least 15 miles......at 2000'ish RPM.......about 15 minutes.
At idle......a LOT longer.
What "should" be inside the cylinder when the spark is applied is gasoline VAPOR, not liquid.
So.....in short......you have WAY more gasoline going into the cylinder(s) than what is normal.......

I was hoping for a "smoking gun"......1 or 2 spark plugs that are super wet...and the others being OK.
Worth hoping for......but at least you know.....even though it was not what we hoped for......and now you have them all with the correct gap.

Aerostar - It occurred to me yesterday that every time I go over there the shop constantly wants to call the Windstar an Aerostar and just about all of them do it when we're talking about it. I looked up the gap of plugs for a 95 3.0L Aerostar (even though my Windstar is a 3.8L) and found the gap to be .042 - .046" - VERY close to what all the old plugs were gapped at.... even still.... none of them were right on the money at one set gap for even that wrong range. I'm 100% sure this is what they did..... looked up Aerostar instead. Thats where I live everybody..... in loser A.D.D.-ville (attention deficit disorder).

If there is anyone that tells you life in Louisiana is any good, they are full of it, aside from the food. The rest of the people here are morons.

Injector harness idea - I was thinking about my limited access to the injectors now that its all back together and I came up with an clever idea. Since I've fully continuity and resistance tested the injector harness to still be usable and good, I do however have full access to the MAIN Injector harness connector just below to the side of the coolant temperature sensor. Its very easy to get to.

I was thinking that I can run various voltage tests here and just see which wires are grounding for extended periods, or IF THEY ARE, because ya'll say I should only see a brief (if any) voltage across the 2 wires per injector. I could just leave my probe connected to the VPWR wire and systematically run through all other 6 wires in that 1 connector..... thereby testing easily all the signals that are or are not getting to the 6 injectors.

Yes, this leaves out the injector connector harness itself, but again I can't reach it unless I take the intake apart again.

Not sure what I'm going to do tonight. Feeling lazy about all this right now. Might just read up on some tech data and tests to do for the ICM and TPS to add to my list of "TO DO's" from what ya'll have told me too.

I found a test to rule out a bad PCM. Very simple and I like it that way.

Basically it says to stick a light probe (test lamp) between test pin 71 or 97 (VPWR) and suspect injector test pin. If the light is "DIM" (key point) then its normal. If the light is "BRIGHT" its abnormal and instantly the pinpoint test says to replace the PCM.

I think what you said here Carl, "What "should" be inside the cylinder when the spark is applied is gasoline VAPOR, not liquid." - says everything. The charcoal black plugs after 10k miles too. It wasn't really oily... there was "some" oiliness to them, but most of the blackness was flat debris-less on the surface coated like wrought iron colored black spray paint..... which I believe comes from all the leftover burnt fuel.

Since all obvious wiring issues have been repaired and I had several electrical anomalies (bad alt, bad battery, shorted - melted PCM wires related to injector's and O2 and fans, blown fuse "s" from injector wiring testing at KOEO, bad dropping resistor) I wouldn't be surprised if the PCM got wacked at some point.

I sure would like to see a BRIGHT LIGHT indicating PCM needs replacing, because maybe then this damn thing will be over with. If this happens I should be able to get the PCM under warranty or at the Shop's cost.

The black would be carbon.
The fuel burning process produces water and Carbon, as the 2 major elements left over.

I've got to tell you that I think this spark plug gap thing is a rabbit trail...

If you get 20 mpg at 2000 rpm at 60 mph, then ...


2000 rotations/minute * 1 hour / 60 miles * 20 miles/gallon * 60 minutes/hour =

40,000 rotations/gallon or 1/40,000 gallon/rotation of the crankshaft. At 128 fl oz per gallon, this is the same as 0.0032 oz for each rotation of the crankshaft.

Now, if you run that engine at idle for one minute, the maximum amount of fuel that can leak out (if none of the cylinders fired, which isn't true because the engine is running) then the amount of fuel available is:

500 rotations/minute * 1 minute * .0032 fl oz/rotation = 1.6 fl oz.



In half a minute, you'd see have as much, 0.8 fl oz. which is not very much (less than two tablespoons). Also, given that your engine is running, then it's less than this amount, probably no more than half as much.

Static flow rates (flow rate of an injector that is held open) of an injector is about 16 lbs/hr. Since gasoline weighs about 8 lbs/gallon, that translates to 2 gallons/hr from a stuck injector, or about 4.3 fl oz/minute. Six injectors all stuck open would offer almost 26 fl oz (a very substantial amount).

I think the large amount of fuel you're seeing is much more likely to come from one or more injectors held open continuously. As wiswind suggested, the easiest check is to check the fuel pressure drop with the fuel pump off which can be done by pulling the fuse, or by simply turning the key off (which will check for mechanical failure of the injector), or turning the key on without starting the engine and leaving it on (since the fuel pump is only energized for two seconds after key on, with the engine off).

Glad you fellas got back down safe from the space station!

I don't think that by simply turning off the key I could do Wiswind's test correctly. I think he wants power still going to the injectors while the fuel pump is disengaged.

No worries, I will be doing ya'lls recommendations tomorrow. I just don't have the patience for it today.

I did however decide to fiddle with my thingy from Hong Kong that finally came in a while back (thingy = OBDI, OBDII, CAN, etc.. interface) and some free OBD softwares I found online. I found about 6 of them I think and tested them all in my Mom's Nissan Maxima. I then tested them in my Dad's 99 Jeep Cherokee Sport.

The test in the Maxima went very well and was able to get a great deal of information from the computer reliably and I found out mom's car is running Lean too. We'd suspected a clogged fuel filter on it for some time now. Unfortunately on my Dad's Jeep there was a communication error/problem so I could never get a good feed of data going.

Finally I went to the Demonic VooDoo cursed Windstar and let the engine run for say 1 - 2 minutes while it struggled along.
-----------------------------------------------------------------------
WINDSTAR OBD2 TEST REPORT:

Connection was made with just 1 of the programs - EasyOBDII cause I didn't want to chance running the engine longer to try others too.

1. OBD2 Compliance - On the 2001 (OBD2) Maxima, the program was easily able to verify OBD compliance. I know 95 was a border year for OBD2 compliance, but the 95 Windstar IS OBD2 compliant, so I do not understand why I wouldn't be able to get this information from the computer if it was functioning properly. This leads me to think further that the PCM is toast, but it could also mean nothing if OBD2 compliance information wasn't programmed into the PCM I have for the 95 year. I do think this is not the case though because this is a 3rd Party NEW PCM that was installed when I had my Original Engine.

2. CLOSED LOOP - Was running in closed loop when I looked at fuel trims and there was definitely not time for the engine to warm up enough to reach closed loop. It was still running fast idle to warm up actually. Though the misfire test completed and did not show an error, we know its misfiring. Along with the CLOSED LOOP msg it also said "CLOSED LOOP, but fault exists" - again this is when I looked at fuel trims. Wiswind - I can't remember what you said it was regarding fuel that was not reported on our Windstars? Could you remind me? Thanks. I'm just hoping this wasn't an erroneous msg. I don't think it was though. Fuel Trims on the Maxima checked out fine and did not say CLOSED LOOP when the engine was still warming up.

3. RICH - Well, we know this too already, but it was nice to see the computer agree. Fuel trim bank 1 reported Rich. Fuel trim bank 2 was not reporting.
-----------------------------------------------------------------------
I can't remember what exactly the O2's were doing cause I was getting nervous about letting the engine continue to run and I was flipping screens and my eyes were dried out too.

I am going to a friend's house right now who has a Ford Truck. I'm gonna test his computer too so I can have another baseline test to work from.

I'm still gonna do ya'lls suggestions tomorrow, but I'm leaning towards a fried computer. It might've fried when Fuse "S" blew during injector installation and wiring repair or more likely it fried when it first started spitting fuel in the driveway a few months back when this pursuit to an answer started.

Misfires - Generically I have found out that they are caused by:

1) spark plugs and wires - We can cross out the Plugs. Wires are 10k miles old, but I still should check them.

2) bad piston rings- you'd be able to tell if you have high oil consumption
New engine, and no high oil consumption.

3) ignition coil packs - Tomorrow I will swap in the old coil pack, just to be sure, but I do not believe my new performance coils are causing problems.

4) THE COMPUTER -"thats right, if many cylinders misfire, you should check that computer module that the ignition coil packs sit on. IT is a big possibility and is a recipe for disaster if it gets really bad. I would have that comp. checked out first." - Gonna have the shop look into this Monday.Found 1 - 4 on another forum just trying to find a usual hit list for misfires.

I know compression can be a cause too, but if this new engine has bad compression I'll be very surprised especially since its from Jasper.

Glad you fellas got back down safe from the space station!


Ohhhhhhhhh man, this was the laugh of my night!! Thanks 12Ounce!!! I think I might have some 12 Ouncer's tonight too! LOL :grinyes::iceslolan

I know right...... Windstars have to be this complicated? JEEEEEEEEEZZZZZZZ!!!!!!

The things we love enslave us.
... some rock song.

As to the fuel pressure test......I suggested doing it 2 ways.
One turning the key ON.....wait a couple seconds for fuel pump to bring up the pressure.....then turn Key OFF.....monitor fuel pressure after key is OFF.
This would see if you have a injector staying OPEN due to a mechanical issue (dirt particle on valve seat, jammed, etc).

The other suggestion was to Turn Key ON.....let fuel pump bring system up to pressure......remove fuel pump fuse.....monitor fuel pressure.
This will see if the PCM is keeping a fuel injector open.
Point here being.....things are somewhat more powered up with the key in the ON position.

PCM....didn't you replace that at some stage?....if so.....do you still have the old one around?


What the OBDII system does not monitor......Fuel flow or fuel pressure.
The PCM does have a connection to the line going to the fuel pump....and could monitor if it has power going to it.....
I do not know if the firmware in the PCM utilizes this input.
However there is NO sensor for either fuel pressure or fuel flow......so we know that the PCM is not monitoring that.

>Glad you fellas got back down safe from the space station!

I think I get the point.

Its too bad that the things we love enslave us and its especially too bad when its a girlfriend you should've gotten rid of 5 years ago. :) Glad thats over with. Too bad it took 5 years. Anyway......

I went over to my friend's last night and tested his Ford F150 with my OBD software. He gets the same "Closed loop" msg I do, so it must be some type of informational msg I'm interpreting wrong.

I did notice though that on his truck the TPS was up above 20% and on my Windstar it was 0.00% at idle. From having worked on my 3000GT before, its TPS sits at 12-14% at idle normally, though it is a foreign make.

Does anyone know if domestic's start their TPS % at 0.00% when at idle?

Wiswind - thanks for the clarity on your test ideas. Will be doing all this later today.

I just checked on my '96 3.8L.
Engine running at idle, reading 725-750rpm, foot OFF accellerator, Throttle Position Sensor gives me 18 on my ScanGauge(1).

I just checked on my '96 3.8L.
Engine running at idle, reading 725-750rpm, foot OFF accellerator, Throttle Position Sensor gives me 18 on my ScanGauge(1).

I wasn't aware the ScanGauge you had gave you that. AWESOME! I would've asked ya to check sooner if I'd of known.

So that leaves me with is the TPS bad or is the PCM bad. Still leaning towards a 2nd burnt out PCM. I will test the TPS today.

Now, today I'm about to go do your tests that you suggested and a couple of my own. The only thing that bothers me though is if the PCM is in fact busted (yes its been replaced by the shop; don't have the ole one, but the old one blew out too just as I'm suspecting this one did) then all the electrical testing I can do till I'm blue in the face (say for TPS, ICM, etc..) is a waste of time.

Ok. I went outside in this area's "Witching Hour" (just before sunset when all the bugs are feasting and buzzing around me) hoping I could beat the bugs, but I couldn't. As soon as I got out there I had 2 horseflies, 1 yellow jacket and 1 wasp circling me as I was under the hood.

Report:
Test 1 - Watch Fuel Pressure with KOEO and fuse "N" (fuel pump) still in the circuit box. Cut off Key and Watch for Fuel Pressure drop rate.Result: Cannot achieve any measurable amount of fuel pressure even with fuse "N" still in. From the time it takes to get from the driver seat to the fuel pressure gauge, pressure fell off immediately. At most I saw it at maybe 10lbs or less.... and then it sharply briskly fell to ZERO.
Test 2 - Same as test 1 except yank the "N" fuse during KOEO. Well, I didn't figure there was much need for this test since it seems obvious the PCM is holding the injectors wide open (I'm right about that right?), but I did it anyway.Result: The pressure was falling dramatically already just like in Test 1.... pulling fuse "N" while it was falling didn't change anything... it kept sharply falling.
I was going to test the TPS and measure voltages at the main fuel injector connector that leads to the 6 individual injector connectors, but again I was being constantly buzzed by insects and I cannot stand the bite of a horsefly.

I wanted to test spark too, but I don't think there is a need (and of course the bugs outside veered me away). All previous plugs, that I pulled a few days ago, being black means I had spark on all cylinders. We'll see though.

My Current Conclusion:
Given the results of Test 1, I think the PCM is fried or something is grounded where it shouldn't be. Having repaired the PCM wiring harness, closest to the EGR pipe area, and seeing no other wiring damage anywhere else I think the PCM is fried. I have no way of knowing if the TPS is fried or if anything else is fried until I can have the shop verify the PCM is fried.

What do ya'll think?

The only thing that I could add is to unplug the whole fuel injector harness....the 1 big plug.
Then see if you can hold fuel pressure.......with the PCM completely disconnected.

On the TPS, one might try (after you solve the fuel issue) pressing the accellerator slightly with the motor running.....and see if you register a reading for the TPS position.

The only thing that I could add is to unplug the whole fuel injector harness....the 1 big plug.
Then see if you can hold fuel pressure.......with the PCM completely disconnected.

On the TPS, one might try (after you solve the fuel issue) pressing the accellerator slightly with the motor running.....and see if you register a reading for the TPS position.

Good show ole chap.

Not sure if this has been mentioned, but before condemning the PCM I think either yourself or the shop should do some quick resistance checks on the injectors, to check if there's a short-circuit between the low end of any of the injectors (i.e. non-red wire) and ground, or between the low end of any injector and the low ends of the other injectors. You can't measure resistance on a live circuit, so that would be done with the ignition switched off.

If there's a connector feeding the high end of the injectors (i.e. the red wires) which you can unplug, then that would be good, because remember those red wires all lead to a common splice point, so when you measure from one injector low end to another, there will be a path up through one injector (14.5 ohms), through the splice point and then back down the other injector (another 14.5 ohms), giving a total resistance of 29 ohms. If you see that then that's ok, just so long as you don't see a dead short between any of the non-red wires.

The point being, of course, that if you have a short to ground then the injector will be continuously activated as soon as the ignition is switched on, or in the case of a short between two or more injector low ends, then the injector would be injecting not only in response to its own signal from the PCM but also in response to the signal for that other injector, thereby injecting too much fuel, and injecting at inappropriate points in the engine's cycle.

And I should have finished off by saying that if you do find any shorts then the next step would be to unplug the PCM and see if they still exist, and that would tell you if the short is internal to the PCM, or external, in the wiring.

Very nice post Selectron. I think what you just said is what I've revealed in what I'm about to write.

I went back outside to perform 2 tests.

Test 1 - Watch fuel pressure drop rate with main injector connector disconnected. KOEO.
Result: Pressure holds fairly well. Drop rate: 2lbs every 6 seconds while above 30lbs; 2lbs every 15 seconds between 20 and 30lbs.

This is still faster than I would expect to see and makes me wonder if my new injectors have been ruined just from 3 tests with the KOEO and 3 tests with the engine running briefly. Though, the faster drop rate may be due to the injectors having previously been open too wide.
Test 2 - Hook up to Injector pin #6 in the Main Injector Connector and hook up to the VPWR wire in the same connector. Measure voltage at KOEO.
Result: 12v (precisely 11.71v) going to all injectors constantly. I make this assumption because of the condition of all the old plugs and having tested injector's #2 and #3 a while back at KOEO and got around the same voltage number. All the plugs were equally black too.

Questions:
1. Do ya'll think from 3 KOEO (engine not running) tests and 3 KOER tests (engine running) that my new injectors may have been ruined?

2. DO I definitely have a short to ground sending 11.71v (or 12v or more when engine on) to the injectors? Seems so right? .. if ya'll wanna be specific... then to just injector #6, #2 and #3... but I'm sure its going to all.

I resistance checked everything (old and new injectors and injector harness while not energized) many posts back. I need to go review that and see and make sure.

And I should have finished off by saying that if you do find any shorts then the next step would be to unplug the PCM and see if they still exist, and that would tell you if the short is internal to the PCM, or external, in the wiring.


I thought if I unplugged the PCM though that I wouldn't even have power going to the VPWR? or is that hooked straight to the battery? I think it is... just can't remember. So in this condition I'd want to test against the VPWR wire and the injector PCM signal wire, but use a chassis ground instead? Sorry, its late and my bio-spark-plugs are misfiring.

What I'm saying is, if you find a short-circuit from an injector low end to ground, or from one injector low end to another, then you would have no way of knowing if that short was in the wiring, or internal to the PCM (because that's where the low end wires connect to). So to determine if the short is internal to the PCM or external, you would unplug it and check if the short still exists. Certainly you would have no VPWR reaching the PCM, but that's irrelevant - you would only be measuring the resistance between an injector low end and ground, or between two or more injector low ends, in the event that you found either of those fault conditions. Resistance measurements cannot be taken on a live circuit, and so long as the ignition is switched off then that that portion of the circuit is not live, and that's the way you would want it to be.

That all becomes somewhat irrelevant though, because before disconnecting the PCM, the battery negative terminal should be disconnected, so the entire vehicle would be powered down at that point. You wouldn't open your computer case and unplug the CPU, or unplug the RAM, without first switching the PC off, eh, and the PCM should be treated in the same manner.

I'm sorry you wrote all that about "powering off" or resistance checking on a "non-live" or "non-energized" circuit, cause I knew that bub. :) I just wanted to know what testing I was doing and why. I get it now though. I gotta do the resistance testing I never wanted to do.... where I have to remove the cowl and access the PCM etc..

Did you see my post 264? I have found the dreaded short to ground fault you spoke of for so long now. :)

I wasn't sure what 'Injector pin #6 in the Main Injector Connector' was, but if that's the low end of injector #6 (light green/orange wire) and if you have 12V between there and that injector's red wire at KOEO, then yes, you have a short-circuit from the low end of the injector to ground, and the injector will be continuously injecting fuel into the cylinder any time the ignition switch is at Start or Run. If you're getting the same result on injectors #2 & #3 with the likelihood of the same fault condition on the other cylinders then that's bad news.

I don't know how your wiring harness all plugs together, but if it's possible to eliminate the PCM without unplugging it then by all means do so, but if not then I'm afraid you have no option but to unplug the PCM to determine if the short is in the PCM or in the harness.

I'd start by disconnecting the battery negative terminal, then measure the resistance from the injector non-red wires to ground - they will likely all be zero ohms - then unplug the PCM and do the same resistance measurement again. If they still read zero ohms then the fault is in the wiring harness, but if the short-circuit has now vanished then the fault is in the PCM.

"but if that's the low end of injector #6 (light green/orange wire) and if you have 12V between there and that injector's red wire at KOEO, then yes, you have a short-circuit from the low end of the injector to ground, and the injector will be continuously injecting fuel into the cylinder any time the ignition switch is at Start or Run."

Correct. Thats what I observed earlier tonight.

If you browse your manual or CD-ROM or alldatadiy thingy under EVTMs, go to bottom of the list Cell 152: Location Index (for Component), then go into Connector, then C100 - C199, browse to C128. In the same diagram note C100.

C128 is the main injector harness connector with 7 pins, 1 being the VPWR and the rest are the colored injector PCM grounding signal pins. C128 is where I've been alligator clamping to (its male pins) to test voltage from VPWR to Injector colored wire since I've reassembled the intake.

C100 is where I'm gonna hope I can disconnect C128 from the PCM without removing the cowl. C100 is a very large square connector with a bolt in the middle of it & where we accessed the PCM harness for repair a couple months ago. However, I think from looking at the diagram that C100 is in a junction AFTER C128 so that might not work.

C103 (stating these for future reference that we'll hopefully use; lol) - Is the main PCM connector by the passenger strut tower.

I'd post photos, but my friend has my web access cut off at the moment.

This is probably a waste of time but it would only take two minutes so it's worth a try. Unplug C128 - you now have a section of wiring which leads to the injectors, and a section which leads to the PCM. Now check the resistance from one of the non-red wire terminals to ground, first on the injector side of that connector, and then on the PCM side.

You'll probably find that the short is on the PCM side, but there's an outside chance that the insulation in the injectors could have failed internally, causing an internal short from the low end of the injector coils to ground. Highly unlikely, but it would be a shame to strip everything down only to find later that the injectors are melted or something like that, eh. Worth spending a couple of minutes on.

If that shows that the short is on the PCM side of that connector, then I don't know if it's even worth gaining access to the PCM just to unplug it, because what are the chances of six separate wires all being shorted to ground? Pretty slim, so I think it would probably be safe to assume at that point that the PCM is responsible for the short. I don't know how much effort is involved though so if it isn't too big a job then you might want to continue, just to confirm it for sure.

Yeah, I think its worth trying and I thank you highly for giving me this idea.... because I was really worried earlier today that the new injectors may have ruined from when I did the tests. Could they really melt from constant 12v? I wonder how long it would take for them to melt.

Even with the PCM disconnected from the injectors the fuel pressure still went down at a rate I thought faster than it should (see "drop rates" in a few posts above). So, I will do your idea tomorrow before I have it sent to the shop.

All this discussion really makes me want to tear it apart at the cowl before I send it to the shop too, but every time I decide to veer from the shop I end up on a week or 2 long testing spree. If the PCM is bad, the shop owes me one anyway. If I could get it tested and back together in the morning early enough before towing it, maybe I'll get to the tests that require removing the cowl.

EDIT: I posted this post when I'd seen post 270. Hadn't seen post 271 yet. Glad that would eliminate having to remove the cowl, though I'll decide if I want to do that or not after I try your post 270 suggestion. - Removing the cowl requires remove the windshield wiper arms from their motors and various layers of cowl stuff.

If it's going in to the shop anyway then I wouldn't bother removing the cowl. I would do that quick C128 test though, just to see if the short is in the injectors, or in the PCM.

Just off the top of my head......the injector internal circuit is a coil.....which pulls a "plunger".....the internal "valve" when energized....
A coil would have a low resistance value.....don't know if there is any resistor to limit current or not......don't know if there is a specification on resistance value....but don't be surprised by a low value......
However.....you should read a super high resistance between the injector teminals and chasis ground......as the only path to ground should be through the PCM.......momentary when the PCM calls for it.

Resistance Tests to known good Chassis Ground C128 Female & Male ends:

NEGATIVE BATTERY CABLE REMOVED.

Injector's harness (female end of C128) to ground:
Result: Zilch. No meter reaction. 0.0L

PCM Side (male end of C128) to Ground:
Results:
VPWR: 0.055 ohm (Confirmed link from VPWR to Ground with no Power on)
Inj 6: 0.9 to 1.5 ohm
Inj 5: 0.0L
Inj 4: 0.0L
Inj 3: 0.0L
Inj 2: 0.0L
Inj 1: 0.0L

New Test using PCM side male end of C128 only (no chassis ground): C128 Inj 6 lead pin to C128 VPWR pin
Result: 0.055 ohm

I'm still at a loss here as to whether this is the PCM itself (now since I've confirmed it to just 1 injector #6 crossing the VPWR lead) or just the wiring. It is a light green/orange striped wire. I'd really be surprised if it was grounded together where the harness melted, because that day the shop owner came over and repaired things I sat and picked through every single wire that was stuck to anything and we focused on repairing all those. He inspected it and so did I afterwards and we were satisfied.

I've only had 4 hours sleep so forgive this question for my clarity:
VPWR wire should always be grounded right? Even when there is no power via battery? Always hot when battery is connected right? - If so, then I am correct to observe an Ohm value from VPWR to Ground or not?

Helping me lean towards the PCM I have the OBD scan software not able to show me the OBD compliance information on the computer (which is available on all other car's I tested), and a fault was said to be present when I looked at fuel trims, and the TPS is not showing up in any % at all and does on other vehicles using the same software.

What ya'll think? I'm about to call the tow truck and I don't know whether I should tell my shop this stuff or not. I am tired of doing their work for them and my findings and thoughts affecting what they decide to do, but if I don't tell them at the same time and they miss this then they might replace the PCM without knowing about the VPWR to #6 grounding.

That eliminates the injectors then - they're certainly not shorted.

The PCM circuits responsible for grounding injectors 1 to 5 are all healthy too, or at least we can say they're not shorted.

So that leaves the PCM circuit for injector 6, which should not be showing that low resistance to ground, and which is of course indicating a fault condition.

The VPWR wire should not be grounded, because that's the 12V supply, and if it really was grounded then it would be blowing fuses. That wire feeds 12V to various engine controls and components (including the PCM and injectors) via the switched contacts of the PCM Power Relay, but only when the ignition switch is at Start or Run. I shouldn't pay too much attention to the reading of 0.055 ohms from VPWR to ground - it isn't blowing fuses, so it clearly isn't shorted. You might have a charged capacitor across that supply rail, which might be skewing the resistance reading.

I recall tripletdaddy recently had a short-circuit in the PCM which was causing injector #6 to be held open when the ignition was switched on - and that's also a '95 3.8L. I think there's a thread in here but I seem to recall that the thread in Engineering and Technical drew more responses. That's here (http://www.automotiveforums.com/vbulletin/t947976.html) - I don't think it will tell you anything you don't already know, but it's interesting that he had the same fault on the same year and model.

Since you're aware that injector #6 is being held open, apparently by the PCM, I think that would be worth mentioning to the shop.

Fuse "S" blew when I was doing injector testing.... prior to the wiring repairs though. I would venture to say it'd blow again if Inj.6 and VPWR are left the way the are.

I told the shop explicitly what as going on. Towed earlier today. I disconnected the battery & C128 before I gave it to them. They are gonna get me new plugs to replace the ones I lost, so I'll have a backup set. The rest well.... should be their fault and on their bill.

About that 0.055 reading... prior to testing I measured my test leads cause I was using the alligator clamps and it came up 0.5 - 0.6. So the test result was really 0.555 - 0.0556 ohms when I tested VPWR and 1.4 to 2.0 ohm when I did Injector 6 color wire. I simply subtracted the difference of resistance observed in the test leads cause i thought I was supposed to. Correct?

In any case when I measured VPWR to chassis ground the meter did react that a path existed and this is with the battery unplugged for a duration of overnight. Could a capacitor still be charged overnight?

Shop says they won't get to it till tomorrow. Here we go again with the waiting of a week... 2 weeks... yada yada... we've been backed up. etc... The Owner is doing it and he'll be the only one touching it too. I will work their nerves to get it out faster.

That is interesting what happened with trippletdaddy. I wonder if we've uncovered a possible manufacturer wiring defect????? or just sketchy 95 PCM's. Oddly though, this PCM is a 3rd party bought one.

I didn't read all 19 pages of this thread (just first and last), but just my two cents...sorry if it's redundant at this point.

Have you considered the crankshaft position sensor? If you have a new engine, perhaps it was installed incorrectly and the engine is therefore not able to control its timing? I think I remember that being the cause of others' similar symptoms occasionally.

Have you tested the rectifier/voltage regulator on the alternator?

Vacuum leak? Air filter clogged? Stuck EGR? Bank ST & LT fuel trim values might help diagnose.

Those are all completely uninformed, uneducated wild guesses, but I guess if you haven't found the problem yet, it won't hurt to mention. Also, I assume you've tried starting the car at part throttle to see if that clears up the idle?

Thanks for chiming in DrZoid.

All things you suggested are good suggestions, though I have ruled them all out except the CranKshaft Position Sensor and a clogged EGR pipe.

I do not think the EGR is clogged though as i'd expect the clog to be at the top by the DPFE sensor and recently I saw the opening there and it was clear. I don't think the little tubes that spawn off the EGR pipe were clogged either as I saw no debris in them when the vac hoses were removed.

I have considered the CKS for a long time now since its the original. Its one of few remaining items that is still original. I would think a fault would be generated if it was bad, but if its OFF that is something I wouldn't know.

Currently though we're on to something for sure with Injector #6 being grounded with the VPWR lead full time. I think its a bad PCM as I have observed this same grounding on injector's 2, 3 and 5 at one point in time before the PCM wiring harness was repaired.

I will look into how to set the CKS though, just in case my MPG issues are not fully resolved when I get the van out of the shop AGAIN.

Fuse "S" blew when I was doing injector testing.... prior to the wiring repairs though. I would venture to say it'd blow again if Inj.6 and VPWR are left the way the are.

Considering that you've had power applied to the circuit plenty of times in the last few days, and the fuse didn't blow, yet upon disconnecting connector C128 you then measure a dead short between VPWR and ground, then it's very likely that you still have an intermittent short-circuit somewhere in the harness. If you were to apply battery voltage under that short-circuit condition then the current flow would be 12V divided by 0.055 ohms, which is 218 amps - a truly massive current, which your battery is capable of supplying, but which would of course blow a fuse almost instantly. So that would seem to be the first issue.

Looking more closely at the resistance between injector 6 low end and ground - 0.9 to 1.5 ohms, and so not a dead short - the significance of that would depend on whether it's located in the harness or within the PCM, which you won't know until the PCM has been unplugged and the resistance re-tested. If it's within the harness then it would cause the injector to remain constantly open but wouldn't cause a fuse to blow, since it only adds slightly to the injector's normal resistance of 14.5 ohms, so the injector would function normally, with the exception that of course it wouldn't respond to switching commands via the PCM since it already has its own continual low resistance path to ground and so would be held continuously open. Or of course it might be the resistance of the now-damaged PCM's injector switching stage for injector 6, if it is indeed damaged, which you won't know until the connector is unplugged.

The final anomaly is that you've measured 0.055 ohms from the 12V supply rail (VPWR) to the low end of injector 6, and then a further 0.055 ohms from the injector low end to ground. So if we look at the total resistance between VPWR and ground via that path, it would be 0.055 ohms plus 0.055 ohms, which is 0.11 ohms, and that would give a current flow of 12V divided by 0.11 ohms, which is a huge 109 amps, and would of course blow a fuse in no time at all. Although of course the fuse would blow anyway in response to the 0.055 ohms between VPWR and ground, causing the 218 amp current flow which was mentioned earlier.

So based on those resistance readings, it looks like you still have a faulty harness, with the possibility of a faulty PCM switching stage for injector 6, with the latter being not yet confirmed.

Finally, consider this: The 0.055 ohms from VPWR to the low end of injector 6 might have a special significance, because the current flow under those conditions massively exceeds anything which the PCM is capable of carrying. Consider the operation of the PCM injector switching stages when the vehicle is functioning normally - with a running engine, voltage will be around 14.5V, which is applied to the 14.5 ohms of the injector coil, causing one amp of current flow. The switching transistors within the PCM will be rated such that they can carry that one amp with some margin of headroom - they might be rated for two or three or more amps and so will be operating comfortably within their limits. Then suppose the wiring harness gets disturbed, and that 0.055 ohm path from VPWR to the low end of injector 6 coil suddenly appears - current will take the path of least resistance, effectively bypassing the injector coil, and so a massive 218 amps would attempt to flow to ground via the PCM's switching stage, inevitably destroying the switching semiconductor (rated at just a few amps) long before the fuse can respond, and blow, since fuses are relatively slow-responding devices. It's possible that that is how the PCM's switching stage for injector 6 came to be fried, if indeed fried it is, which you won't know until the PCM connector is unplugged and fresh resistance readings taken.

PROGRESS!!!!!
If the short to ground from #6 injector.....unplug the fuel injector wire harness.......if short is still there....then it is in the injector wire harness.
If it is gone....it is from the fuel injector wire harness plug....through the PCM.
You could unplug the PCM to see if it is the PCM or inside the wire harness from the fuel injector harness plug up to the PCM plug.

You could unplug the electrical connection from fuel injector #6 and see if you hold fuel pressure with everything else connected.........

Just read the last 2 posts. Thanks guys.

Very fine analysis Selectron. I have always thought about going to school for electrical engineering to become familiar with the limits of certain electrical devices and circuitry. While my knowledge is greater than most in this area, I still don't know things like "what amperage can this or that run" and what amperage or volts would be produced by certain situations (shorts, regular setup, etc..) so its very helpful having this technical information.

Wiswind - I cannot describe how invaluable you and this forum is. In several occasions and perhaps even more than 90% of the time the responses and persistence in this forum represent humanity at its best..... caring, giving & helping with only the reward of feeling good about it. While we know an alternate purpose of this site is to run ads and make money, at the same time it does function as a place people can go to network using the best qualities of humanity. I know its all sappy n all that, but I feel this thing finally drawing to a close.... ever since February 2008 when the Jasper engine was installed. Its never run right since then and this has been why.

Thank you all for the best of your humanity.

On an another note, I had initially thought when I was reading ya'lls posts the following thought occurred to me:

Does it ever bother you all that it always seems like 1 more test, 1 more test, 1 more test, 1 more test, 1 more test, 1 more test,... etc... till you get to the bottom of whats going on?

1 more test - makes me feel so exhausted before I even lift myself up to go do the test, because I know it will lead to 1 more test. :) I just see it like an infinite loop in programming code. I keep believing, "IT CAN BE FIXED" and "THERE IS AN END IN SIGHT" .... but it always seems like "1 more test". I try to keep it that simple too, because if I think its gonna result in 20 more tests.... I get really discouraged. "1 more test" is kinda like a trick for my mind to keep going without losing the sanity. lol

I think the shop thinks I'm frakkin insane or maybe they cannot believe someone of my magnitude of patience, especially on what most people tend to not care about...... "AN OLD VAN". I just cannot begin to describe what having a VAN does for a person. Forgetting all the stupid stereotypes that exist about VANS, Vans allow you to do as much if not more than trucks. Mini van or regular... they accomplish a great deal.

This thing was never supposed to be a vehicle that I repaired. When I first got it, it was intended to be a weekend "get-away to the beach" vehicle that I'd sleep in to avoid hotel fees and come home (4 hours to beach and back), but shortly after I got it I started to learn the benefits of having a large capacity A/C enclosed big vehicle.

What this has turned into is far short of fixing a van. It has become almost a science project. It is probably the longest learning experience of my life and I'm much better for it now as it has broadened my understanding of what I never really knew that well, "How an automobile functions", and not just the basics..... the deepest stuff.

Well, enough tree sap. :) Just wanted to say a few things.

As it stands now, van has been in the shop since late Monday afternoon and I haven't heard anything yet as usual. I'm gonna call'em tomorrow and see if they've even started it.

Day 3 at the shop come and gone. Haven't even touched it yet. :( I guess its what I can expect since I'm asking for "special service" as in I've told the owner that I only want him working on it. Hopefully he will get to it tomorrow.

I almost freaked when I called over there cause the other owner said the main owner was out test driving and I thought he meant the van and had not begun working on it yet. That would've been bad news. lol

In any case I hate when momentum is fouled by something like this. Steams me up.

I think I will be going to visit my gf 330 miles away soon, so maybe the van will be done when I get back. :)

Thursday - June 11, 2009 -
Talked to the shop owner and he'd finally gotten to it on Wednesday actually and I am still out of town. Missed his call and caught him Thursday.

Well, my and you guy's efforts recently paid off. PCM it is. The shop owner ohm'ed things out for himself and as soon as he disconnected the PCM the grounding of injector 6 and VPWR went away.

He actually only confirmed injector 6 and I don't think confirmed VPWR, but I told him before he powered it all up to make sure to check the ohms on both wires. I dunno if he'll actually do that or not, but I do know I'll check it before I drive away with the van. I guess with inj 6 verified to ground in the PCM he didn't feel he needed to test the VPWR circuit due to the wiring repair job we'd done prior.

The PCM will be FREE!!!! It was put in however in 2007, but the shop owner worked the deal with the manufacturer somehow to get it in a warranty swap.

The 2nd PCM (this new one will be the 3rd) was put in when the original engine was in there. I dare say this problem existed all the way back then cause similar wiring mishaps and sensor's blowing out happened just after that 2nd PCM was installed. So its likely that someone at their shop prior to the engine replacement mis-routed the PCM wiring which caused it to melt etc...

Anyway, I get back in town to pick it up Monday or Tuesday at which time I'll test it and drive it and listen to it run etc.. and post back. I just hope now we're done chasing ghosts in the machine. If the MAF (AFM) blows this time right after the new PCM is installed I will get a shotgun out and shoot the van, cause thats exactly what happened immediately following the 2nd PCM installation as soon as I drove off the repair shop's lot. :) I guess I'll be hopeful again though, and hope for the best.

Hey! That sounds great! I thought you fell silent because you offed it and was in jail, or you took it off a cliff putting you both up in a ball of flames.......if you were so lucky. I guess not. I didn't think there are any cliffs in Louisiana or any high enough to do any harm. Sorry I've been silent as I've been snowed in with my own tail chasing.

I wanted to tell you again, but I'm pretty sure I said what you have sounds like what I had with the injector grounding out causing the injector to be open or on all the time. I think I determined that the injector was grounded only when the key was on with or without the engine on, so the PCM was doing that. If it's grounded at all times, no matter what you do or don't have connected, it will be a hard ground through the wiring harness, or the injector itself is grounding to the head. Since you had the wiring harness melt, you most likely fried your PCM as you already suspected, but it could also have been the initial grounding of the injector if not the only ground.

Another symptom of this problem besides gas leaking at the exhaust manifold and in the exhaust gas at the tailpipe, is the fuel pressure will not stay where it belongs at KOEO. The pressure will go up when first turning on the key but will go to zero because the shorted injector is open and will let the gas out. I'm pretty sure the power to the injectors, and a lot of the other sensors, etc., are powered by VPWR (red), as soon as the key is turned on. The circuit to each of those devices, like the injectors, won't be completed until the PCM provides a ground to it. I'd guess either the melted harness and/or the PCM took out your MAF as well. Seems to me the shop that misrouted your wiring harness should have to install a brand new one and anything else that was taken with it, like your PCM.

To check to see if your injector wiring is ok, you need to check to be sure the colored wire is not grounded when KOEO. If you have a hard short, you will have a short in that wire with the engine off, but I don't recall if the PCM normally grounds that and the red, power wires when turned off. You only have power at the red when KOEO and Engine ON, and it should be about one volt within BAT+. I can't remember if red (VPWR) will be grounded by the PCM or open when the key is off. To do these tests, you may be able to pull the connector to your 6 injector, but I know it's tight getting to it as that is the one I had go bad, which I find very peculiar and interesting we had the same one go bad. Hmmmmm. I think you should be able to get some meaningful measurements by piercing the wires with a pin or needle near the injector rather than strugging with disconnecting the injector or the PCM. Since I had to remove my PCM, it was easy enough to check the resistance and shorting to ground of the wiring to the injector. You could do comparative measurements with another injector wiring. The OEM injector resistance should be around 7 - 16 ohms. A circuit that should not be grounded will have at least 10,000 ohms resistance. The Ford TSM, I think you said you have covers this, albeit it took me awhile to work through it. The HD - Misfire .... pinpoint test section covers this pretty good. The pinpoint tests are what you want in the PCED, OBD Manual section. Boy, you lucked out on a new PCM. Wish I could have fallen into that, but at this point, I think you more than earned it, as you have the greatest stick-to-it-tiveness I ever heard. I still can't believe you didn't sink it in the bijou or torch it!?!

Finally, if the mechanic has the van running, which I assume he will when he says it's fixed, all of the above will be moot as it will have to be correct in order for everything to work correctly. I'd only worry about incorrect values, shorting, etc., if it isn't working correctly, you get codes, etc. Did you have any codes? I had a misfire code, but for cylinder 1 not 6. The misfire detection explanation did not explain that scenario.

Tripletdaddy - Fun reply to read and all great points. :)

I wish I had great news, but as usual its only half great.

Status:
1. Returned home yesterday and picked up the van this morning.

2. Test drove it mild, medium, and hard around town and interstate. Seemed fine, but little blip when the radiator fans turn off is still present. I was very very very very very disappointed to feel/see that happen as I know it means there is still something electrical not right. Its not like a "almost stall" now, but more a fast blip where the RPMs dip and come right back up instantaneously.

3. I don't believe it has the power it is supposed to have on the road. It doesn't feel strong like it used to, but I cannot be 100% sure since I've been driving my sports car around in the interim.... though I'm mostly sure it doesn't feel strong. I don't make a habit of getting up to 90mph, but I had to test it fully and between 70-90mph there's a struggle to increase speed. 90 seems to be about all it can do too, which is new. Again, I don't make habit of driving that fast, but I've had it easily at 90 or 95 before without it seeming like it was struggling to get to it.

So..... then.... once home:

NEW TEST RESULTS:

This is ME testing to verify what the shop did. Remember they had it again for 2 weeks.

!!!!!!! DISCONNECTED BATTERY !!!!!!!

GOOD NEWS: Injector 6 and all other injector wires are not shorted to ground.

Test 1 - BAD NEWS: Connected to known good ground & ohming at VPWR in C128 main injector harness connector.
Result: .554 k ohm (not .0554) every time reliably and without use of alligator test clamps. This was probe to probe and my meter probes test 0.00 resistance prior to testing circuits.

Test 2 - VPWR C128 wire to positive battery terminal while positive cable still connected, but negative battery cable still not connected.
Result: .4m ohm ranging up to 4.90 k ohm

Test 3 - VPWR to neg batt cable, batt not connected
Result: .554 k ohm reliably
*I think I should've seen NOTHING happen here, but did.

Test 4 - ECT wires from VPWR C128 main injector connector for comparison
Result: ECT Gray w/Red to VPWR C128: 0.554 k ohm reliably
Result: ECT Light Green w/Red to VPWR C128: 19.33 k ohm steady
*I think I should've seen NOTHING happen with the Gray w/Red stripe wire.

Datalogger information:

TPS 14.9% (Glad to see this reporting now)

Ignition Timing Advance Cyl #1: 26 degrees at full hot

O2 Bank 1 Sensor 1: Rich
O2 Bank 1 Sensor 2: Rich
O2 Bank 2 Sensor 1: Lean/Rich switching
O2 Bank 2 Sensor 2: Rich
*On all 4 though once vehicle was fully warm they seemed to switch Lean/Rich pretty fast though warming up most of the time were Rich.

Load calculated 36% at idle with A/C on

STFT Bank 1 switches Lean/Rich at full hot
STFT Bank 2 switches Lean/Rich at full hot

LTFTB1 15.69% Rich at full hot
LTFTB2 11.72% Rich at full hot

OBD Compliance still not available, but now I think cause its a new PCM this is just how it was in 1995... no compliance maybe was yet available at the time OBDII came out.

Comments welcome on Datalogger findings. Anyone else and Selectron too.... I'd like to hear chatter on the circuit testing I did. I know we've repeated a lot, but from what I see I still have a VPWR short to ground. CORRECT?

The story of horrible bayou voodoo continues....

What is the best method to trace where VPWR may be shorted to ground?

What is the most likely place (at this point) to check for a VPWR short to ground?

I have been trying to think of everything thats been touched in that engine bay and of what circuit board type components still haven't been replaced. The ICM comes to mind as one of the few remaining not-replaced circuit board parts, but that may not mean anything if the harness is just shorted somewhere.

I have asked tripletdaddy if he can perform a multimeter Ohm test on the same VPWR wire to Ground (batt disconnected) on his 95 3.8L Windstar to get a reference from another vehicle. Hoping he can do it. Would be nice if any of ya'll could try the same test on your year Windstar. Wiswind's 96 would be a good test too... and anyone elses. I know I'm not supposed to see a value reported for this test, but it'd be nice to see if anyone else does cause then maybe its "normal" for possible residually stored electricity in the system somehow.

I think the fact that when the radiator fans turn off and I see the idle blip down once and then again twice EXTREMELY FAST before normal idle returns, shows that all my wiring work and improving of grounds has weakened the problem whereas before it would almost stall. Now it just seems to be a half second to second dip in idle speed.

Sorry to hear you still have the blip, Searcherrr, it must have been a big disappointment. :( The resistance test results look good at first glance - I don't see anything to worry about, but I'll take a closer look at them.

Test 1: 0.554 kilohms (554 ohms) from VPWR to ground - that's fine - see my comments for test 3.

Test 2: Conventional multimeters aren't capable of measuring 0.4 milli-ohms, so I'll assume that 0.4m (lowercase, so milli) should be 0.4M (uppercase, so mega). That would give readings of 4.9 kilohms (4,900 ohms) to 0.4 megohms (400,000 ohms) from VPWR at C128 to battery positive terminal. VPWR doesn't get 12V directly from the battery; instead it takes it from the switched contacts of the PCM Power Relay, which was switched off at the time. Therefore there was no direct path between VPWR and battery positive, so what you have measured is likely an internal resistance within the PCM between the VPWR inputs on pins 71 & 97, and the B+ keep-alive power input (KAPWR) to the PCM on pin 55, which is indeed connected to battery positive at all times, to preserve the PCM's volatile RAM data. Without an internal schematic for the PCM, what that path actually consists of is anybody's guess, but it's safe to say it won't be purely resistive - there is probably considerable circuitry between the two points, and that's what you see on the meter but you can't really draw any conclusions from it. The variation in resistance would have been some of the PCM's capacitors taking a charge via the meter's probes. Having said all of that though, testing resistance between those two points is fairly pointless and not worth repeating.

Test 3: 0.554 kilohms (554 ohms) from VPWR to battery negative cable with battery disconnected. The battery negative cable is at the same potential, electrically speaking, as vehicle ground, so this is the same measurement which you already did in test 1 - hence the same result, so these comments also apply to test 1. Just to explain where that reading of 554 ohms comes from, imagine that you're working on a lighting circuit and you're testing resistance at the 12V feed into a bulb. The battery negative cable is disconnected. Now when you put the meter's positive probe onto the wire which feeds the bulb, and the meter's common probe onto a ground point, you are effectively measuring the resistance through the bulb, eh, so you will see the lamp's filament resistance with, perhaps, other paths in parallel depending on how the circuit is configured. So when you put the meter's postive probe onto VPWR and the common lead to ground, you're measuring the resistance through all the components between the two points, which by the way is many. If you look at the wiring diagram and follow VPWR back to its splice point, you'll see it branches off in many directions. Follow it further and you'll see it branch again, and then I think it branches again, because it feeds a whole host of ignition and emissions systems control devices and sensors. The easy way to visualise that is as a bunch of resistors connected in parallel between VPWR and ground, and you have measured the effective parallel resistance between the two points. Once again, having said all that, the actual resistance figure which has been obtained tells us little except that you don't have a short-circuit to ground, so in that sense it was worthwhile.

Test 4: Resistances from VPWR at C128 to each terminal of the ECT sensor. I shouldn't pay too much attention to those readings. The light green/red wire connects to PCM pin 38, and there's no way of knowing what resistance might be expected between there and VPWR, and then the ECT's grey/red wire branches off all over the place, with series resistances of various sensors along the way, likely with some of them effectively in parallel, thus forming an intricate little series-parallel network, so without knowing the resistance values of all the components, it's not possible to know what resistance might be expected between that point and VPWR, and even if we did know the values, there would still be paths within the PCM for which we could not account, so it really is almost impossible to interpret.

So that all looks good to me, and there's nothing that I would be concerned about.

VPWR is not shorted to ground. If it was and if you applied 12V from the battery then there would be a massive current flow - maybe many hundreds of amps depending on the exact resistance. In fact though you have 554 ohms between VPWR and ground, and if 12V is applied then the current would be 12V divided by 554 ohms, which equals 0.0216 amps - in other words, a mere 21.6 milliamps. That's about the same tiny current which flows through a regular old-fashioned low-intensity LED. It's hardly any current at all. It isn't a short-circuit.

I have a digital multimeter from RadioShack and it did show a lowercase "m" on it. I don't know if that means anything except that you know what kind of multimeter I have, but there it is.

Yes, it was a huge disappointment that I still have the blip. Huge.

Thanks for your reply Selectron. I understand your explanations and glad to know them. All I can say is..... "OH." - I'm glad that I don't have a short-circuit to ground, but of course I am still left with the fact that the idle dips twice after the radiator fans cut off. I might assume this is just normal vehicle behavior, but I will never believe that. Only reason I'd assume that is because it used to do this very very very slightly so in the old original engine too. For whatever reason it became very pronounced when the new engine was installed. I wonder if that in itself is a clue.

I haven't tried calling Jasper to report this, but I'm not sure what they'd say. I have tried replacing the rad fans themselves with no luck. Other than that I really wouldn't know where to start cause we've really covered just about everything else there is.

I suppose I can just drive it a while and report back the mileage. I haven't tested fuel pressure yet, which I should. I'll report back with that.

Yes, it's difficult to know where to go to from here eh, because pretty much everything has been considered by now except the tyre tread depth. http://www.automotiveforums.com/vbulletin/images/icons/icon10.gif Oh yes, I remember now - the fuel pressure testing had to be abandoned when the #6 injector driver went short-circuit. I suppose that would be a good point at which to restart testing then.

Fuel pressure is 26 - 28psi. 28psi at idle and it never goes higher. If my system is running right, as it should be now, this would indicate the Ford CD-ROM being wrong everywhere it mentions the pressure should be 30 - 45psi and contradicts all the Ford dealerships I called too. There is one place on the CD-ROM though that states 28 - 30 psi is normal, but that is in a data table that lists all kinds of other information too. Is that data table the only place on the CD-ROM that is correct for the fuel pressure?

26 - 28 psi is when I throttle the pedal.

28 psi is when its idle (again).

Belt is squeaking like mad. I had gotten rid of this until it went to the shop the last time. Only thing I have left to do is replace the belt with a Ford OEM belt. All other tricks have been tried and its extremely aggravating. Its like its shoving its finger in my ear when I'm driving..... after all that care... furiously squeaky belt.

Lastly, I am not sure if this means anything, but the day I got it back I topped off the fuel tank till the pump stopped it 1 time. Usually you can fill it up more and the pump will stop it 1 or 2 more times, but I didn't do that. I stopped when the pump stopped it 1st time. Before filling it I'd noticed the gas meter was at E bottom mark with the light on. I figured at this point I probably only had 2 gallons left, but it only took about 21.5 gallons and its the 25 gallon tank.

Now only after 12 miles the fuel meter is showing the needle just below the blue FULL mark. Did I not fill it as high as I could've? or is excess fuel consumption still an issue? No gas leaks anymore.... none that can be seen. Wonder if I should suck it up and finally put that OEM coil back in there.

EDIT: Forgot to mention, FUEL Pressure rose to 34 psi once I'd turned the engine off. That was new. Never seen it hold pressure that good before. Is it a concern that it rose 6 psi after the engine was off ?

I am utterly beaten down by this problem. It makes me want to involve Jasper to find out what is going on. I'm sure their problem solving skills would either find the problem or prove their reman engine has issues.

I am at 1/8 a tank and only have gone 17 miles. Though as I found out today when I went to change the oil, as told, I found the PCV vacuum hose was completely disconnected. I'm more than positive the shop did this. I asked them what they disconnected and the intake pipe was it. I know I didn't leave it that way.

So now for the past 14-15 miles (when I reconnected it) I don't have a good basis for MPG calculation because I had a certain large vacuum leak just before the throttle body.

Now that the vac hose is plugged back in I'll drive it to 1/4 or 1/2 tank and see what my mileage is and do cruise control for as much of that as I can and see where it takes me.

I was going to replace the Performance coils with the OEM coils today, but after I found the pcv hose disconnected I figured I'd drive it around in proper configuration before putting the OEM coil back in.

I will be surprised if the OEM coil changes the situation or improves MPG, but we'll see.

I still have 2 idle blips (falls) after the radiator fans turn off.

After talking to tripletdaddy via PM I'm gonna try a couple more grounding tests related to the CCRM and PCM as soon as I have the patience to push forward again. The grounding black connector near the battery above the radiator I believe is the PCM ground wire. I want to recheck this as I seem to recall testing it produced unreliable results, but I can't remember if it was me or the test that messed up.

Well, is good MPG 35 miles to 1/4 a tank?

How on Earth can this be? Almost, everything is new, no codes.... I just do not get it. Shop tells me to drive it 2 or 3 weeks, but I've been this route before.

I don't believe the computer learning period would deduct more than 2x the MPG I should be getting. IF so then you'd have a lot of pissed off people in vehicles of all makes complaining of horrible fuel economy.

Is it possible the O2 sensors could be causing this without throwing a code? I know we've covered those before and Wiswind reported no difference in MPG after replacing his (no codes), but is it possible that the O2 elements are poisoned from fuel or my cleaning procedure using electrical parts cleaner to where they'd throw off erroneous readings?

Grasping at straws now. Don't know what else to grasp at.

If every repair makes the gas mileage progressively worse what is that likely to mean? Seriously, every repair has made the MPG worse or just not improved it. The new PCM made the MPG much worse by about 3-4 mpg less.

Is this the tell tale sign that something electrical yet exists still? Tell tale sign of anything?

At 5/8 of a tank (about 3/8 tank down from full) and only 50 miles on odo. :frown: Used to see 50 miles by 1/8 tank down.

I would go by how much fuel you add to fill the tank up......as the level indicator likely was changed at some point.....and can vary slightly.
I would guess that the first thing is to have the vehicle running properly......and see how a couple tanks of fuel do......from full to under 1/2 of a tank.
The drivability learning should take place well within 1 tank of fuel.

Dunno Searcherr. You've replaced so many things especially so close together in time, it would be hard to guess and pinpoint the source. Assuming all else is in good working condition, I would be suspicious of the PCM not operating the engine at top efficiency, thus needing to be reprogrammed. I'm not sure how to go about proving that without researching it, but I'd think the use of a data recording scanner would help. No codes? If so, that doesn't leave much else besides the PCM. The PCM will code if there are problems with the ICM. Perhaps having it hooked up to a dealer like computer analyzer, the really expensive ones, will be the only way to determine what's the problem.

I guess I could bring it to the dealer, but I don't even think they have the tools to scan this old vehicle anymore. I really don't even trust the dealers out here. I've had bad experiences every single time going there. Maybe I can call them and see if they can even analyze it. I mean if all they do is check sensor outputs, I already have that. I need a real analysis scan that actually points to something.

Refilled the tank today with 7.937 gallons.
Had driven 73 miles (just shy of 1/2 a tank).

73 / 7.937 = 9.20 MPG

Thats city and hwy combined.

Going to put 2 new upstream O2's in tomorrow & put OEM coil back in too and then see if MPG changes.

"Going to put 2 new upstream O2's in tomorrow & put OEM coil back in too and then see if MPG changes."

You really are grasping at straws!?!

I would expect you having codes resulting from problems with those things you plan on replacing if they are the problem. I don't expect much of a change from changing the coil. Have you pulled any of your plugs to see how clean they are? Or strength tested the spark to the plugs? Both would give you an indication of things not right.

Clearly you have a fuel efficiency problem and no clear cause since most everything checks out or is new, that's why I wondered if the PCM you have isn't exactly right for your van, which is why I wondered if reprogramming it might fix it or at least it be checked to be sure it is right for your van. Your pre-O2s do influence the fuel based on the voltage signal they send to the PCM, with the ideal air to fuel ratio of 14.7 to 1, at least that's what the PCM is supposed to try to get. If you have no codes for them, can your scanner can pull the O2 outputs? The normal operating range is 0.1 volts (very lean) to 0.9 volts (very rich). You can if you want to test them right at the O2 connectors by backprobing them at the SIG wire (positive) and your neg. on a good ground. They warn not to pierce the wires or use an analog meter for these measurements. I assume with cold engine, turn KOEO, you should get between 0.40 to 0.45 volts. If not, then you have a wiring problem. Gees how new!?! It would be a good time to be sure you have good batttery voltage too, 10+volts. Then warm up your engine and you should see the SIG output switch between high and low readings within the previous mentioned range. The post 02s aren't supposed to switch up and down but keep a steady reading also within the same range.

Hmm, is there any chance that you have any parts that have been replaced that are not the right one for your van? Maybe a parts store or shop mistake? Could happen, but thought that might explain things. I don't know, there are SOOOOO many things to check that could be it!?! CKP, ICM, engine compression....stowaways. You hauling a bunch of mexicans around you don't know about? That could kill your mpgs. You get enough of them hiding in there, that's a lot of weight!?! I bet you never looked or thought of that did you. :iceslolan