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

[searcherrr]

EDIT: NEW START & THREAD SUMMARY AT POST #129: http://www.automotiveforums.com/vbul...90#post5849490
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Start of original thread:

Description of Problems:
1. I'm getting 9 - 11mpg on a new Jasper engine
2. Idle pulses/hunts constantly in Park from 600 - 800 rpms
3. Sometimes under accel/load driving the van jerks. Its actually hard to describe what it does, but its as if it can't make up its mind about going forward or possibly what gear its in or like it isn't getting gas or something.
4. Engine attempts to stall IMMEDIATELY following the radiator cooling fans turning OFF. This has made me think perhaps the CCRM is going bad because I don't know what else would do this unless its an electrical (bad ground) issue.

I'm not sure if the 2 (MPG and idle pulsing) are related, but I believe them to be.

I believe the van is running a little hot at idle. It has gotten up to between the R and M which is higher than it ever used to go though I observed this with only the Ypipe attached and the rest of the exhaust wasn't which may have had something to do with it. It religiously used to stay between the M and the A on the temp gauge and since the new engine its always in the M to R range on the temp gauge. Was thinking it could be that I didn't use a Motorcraft thermostat, but it also could be related to the idle and MPG issues.

Things tried:
New cats (Magnaflow ypipe)
New cat-back exhaust upgrade (Borla discontinued model)
New O2s (putting old ones back in after cleaning them if they still work from cleaning)
Cleaned MAS/AFM
New engine
New plugs and wires
Rebuilt tranny 20k old
New VSS
New TRS (neutral safety switch)
New water pump
New IAC
New thermostat (not motorcraft, but supposed to be OEM temp)
New radiator with system flush
New PCM
New battery
Regrounded alternator with better cable
New DPFE sensor
New coolant/heater hoses
New ABS HCU
New alternator pulley (tracking down a squeaky belt)
New compressor clutch assembly (though I've noticed now the compressor is leaking)
New power steering pump and filter
New accumulator for a/c
New brakes/pads in front (no drag)
New (fairly) pcv valve though I could check it again
New air filter (K&N)
New fuel filter 8k miles ago

Thoughts!?:
1. Plug gap accurate? Supposed to have been set from factory - Autolite Iridiums

2. VSS (speed sensor) - The new gear I had it come with. I'm hoping I was not given the wrong gear from the 3.0L engine as they said they made sure it was for the 3.8L engine, but this could cause bad MPG.

3. Alternator/Grounds - Tests fine a while back (could test again with my multimeter) and always has though I have my eye on it for failure as just about everything else is new. I almost want to replace it just because its so old (158k), but as the O2 sensors have shown me I probably shouldn't. I am worried though about the grounding in the engine bay as if I were to remove the cable from the alternator to the frame the van will not function AT ALL and I mean no power to anything inside. Is that normal? Could this mean the battery isn't grounded well at the negative terminal/cable?

I have also noticed the instrument panel lights dim out a lil bit after I let off the accelerator and then they come back to normal brightness instantly. There are times too when I press either door lock buttons or window buttons on either door that there is absolutely no response and it takes a repress of these buttons to get the locks/windows to work. Does this speak to a ground issue?

4. Could the a/c compressor leaking cause drag on the serp belt?

5. CCRM?

6. Ultimate question: Why does the van try to stall when the radiator fans TURN OFF and ONLY at this point? It attempts to stall at NO OTHER time.

7. Should the coolant fully remove from the coolant reservoir? It stays at COLD level even when hot. Also, the tranny cooler was never cleaned or replaced after my overheating and water pump failure. I'm unaware since I didn't install it if there is coolant or just tranny oil going through the tranny cooler. The cooler I'm talking about is in front of the radiator at the very front of the van and looks like a mini-radiator.

[searcherrr]

On my other car when the coolant temperature reaches the same temperature (within about 3 - 5 degrees at MAX) the cooling fans kick on. Apparently from observation my Windstar isn't turning on the cooling fans consistently. The temperature seems to variate a lot bouncing between the R and M and A on the temp gauge before the fans kick on. Could this indicate a faulty coolant temp sensor (ECT)?

[searcherrr]

The shop manual says the coolant reservoir helps to maintain the correct volume of engine coolant. I have let the van sit running for 30 minutes several times and the coolant level in the reservoir NEVER changed. The manual points to obstruction in the coolan reservoir line or a faulty radiator cap. I think after all I've spent spending a few bucks more to get a new rad cap is worth it. I'm gonna pull and inspect the reservoir hose as well. I'm approaching this for once now with "lets deal with the symptoms" rather than the backwards way and the symptoms are that the temperature gauge is not holding steady like it used to on the old high mileage engine, when the cooling fans turn OFF the van tries to stall at idle and the coolant reservoir level NEVER changes.

[wiswind]

You might try a new radiator cap....as cheap as they are.
Mine gave me problems in maintaining pressure......I had to keep messing with it as I kept finding that it was not holding pressure.
I got the normal cap.....no pressure release thing....just one that was just like the OE one.

I don't know if a new CCRM would help or not.
Only way to know is to change it.......more money....but then it is old.
Mine needed replacing 2 times......the 2nd time was because the A/C relay was not holding the A/C compressor on.....following the A/C cycling on and off a lot when the A/C charge went down......due to a leak in the evaporator coil.
So....the CCRM might be worth a try.

Another test.....you could try unplugging the radiator fans VERY TEMPORARILY to see if the stumble still happens.

The tranny cooler inside the side tank......on the passenger side of the radiator and the tranny cooler in front of the radiator (if equiped) both have ONLY transmission fluid flowing through them.
Inside the radiator......the coolant flows OVER the fins of the tranny cooler.

[searcherrr]

Per this thread: "Dropping Resistor" - I have checked my dropping resistor and its broken. It wasn't "all the way" broken, but it was cracked all over, pieces off, and was on its way out. This could be the cause for my fan cut off issues though I don't know about the MPG issues.

I've ordered a new radiator cap and new dropping resistor to solve the coolant level problem and the resistor to hopefully solve the near stall problem at low fan cut-off. We'll see.

O2s - I put the old freshly cleaned O2's back in tonight and rebolted everything. I started it up twice and let run for just a couple minutes cause of no low fan speed. I did not receive a CEL so I'm assuming my O2's are ok since my cleaning of them and since they are self heated. I don't want to do a full test to operating temp though until I get my low fan speed operation back. Meanwhile I'll see if Autozone will take back the other O2's which may be a doozy cause the couple of startups I did, DID change the look of the sensor guard/tip. I'll see what a lil cleanup can do. lol - If not then I'll have to try and sell'em here or on Ebay cause I need the cash.

[searcherrr]

Wiswind - thanks for the suggestions btw.

I know the CCRM is responsible for current and turning stuff on and off, but could the CCRM be indirectly related to bad MPG? Have you known it to be?

[searcherrr]

Food for thought. I read tonight that O2 replacement on OBDII systems for the sake of preventative maintenance is pretty much a waste of time. On OBDII systems you are either gonna be alerted by the computer that its failed or notice it big time some other way. The worry about O2 replacement for preventative maintenance is mainly for pre-OBDII vehicles.

Now I don't feel so bad putting the old ones back in. I realize they slow down over time, but this may be due to deposit buildup on the sensor element itself which I hopefully eliminated with my cleaning process. If its due to degrading of internal ceramic though thats a different story.

[LeSabre97mint]

Hello

I would look into the battery ground cable. Check it for internal resistance. It could look fine on the outside but be totally rotten on the inside. The fact that if you remove the alt ground and you don't get any life means that other grounds aren't being effective.

You've practially replaced every thing on that van!

One good check is to put your volt meter on the battery ground and on a good ground on the body. Watch the meter when the fan shuts off. You might see a spike or a drop in voltage???.... I know that the ECU doesn't like drastic voltage changes. I had a vehical that the engine would stumble when the fan turned on just for a bit. Those fans really do draw the juice.

I take it that you didn't experience this poor millage and poor running before the new engine was installed. I also take it that you didn't install the engine. I always say "just because you pay someone to do something doesn't mean it's done right".

On my 98 Windstar, which I had bought with right front body damage, I had to remove much of the wiring in the engine bay on the front of the sheetmetal inferstructor. I missed a ground wire on reassambly (the hole had been welded shut). I had some really wierd things going on. Flashing ABS and Brake light, with a clicking noise under the dash. I still have airbag and SEL issues. They could be because I missed another ground wire.

Regards,

Dan

[searcherrr]

Originally Posted by LeSabre97mint

Hello

I would look into the battery ground cable. Check it for internal resistance. It could look fine on the outside but be totally rotten on the inside. The fact that if you remove the alt ground and you don't get any life means that other grounds aren't being effective.

You've practially replaced every thing on that van!

One good check is to put your volt meter on the battery ground and on a good ground on the body. Watch the meter when the fan shuts off. You might see a spike or a drop in voltage???.... I know that the ECU doesn't like drastic voltage changes. I had a vehical that the engine would stumble when the fan turned on just for a bit. Those fans really do draw the juice.

I take it that you didn't experience this poor millage and poor running before the new engine was installed. I also take it that you didn't install the engine. I always say "just because you pay someone to do something doesn't mean it's done right".

On my 98 Windstar, which I had bought with right front body damage, I had to remove much of the wiring in the engine bay on the front of the sheetmetal inferstructor. I missed a ground wire on reassambly (the hole had been welded shut). I had some really wierd things going on. Flashing ABS and Brake light, with a clicking noise under the dash. I still have airbag and SEL issues. They could be because I missed another ground wire.

Regards,

Dan

Thanks Dan.

Yes, the old engine ran good MPG as far as I was concerned and the shop did install the engine and it was their 2nd install of an engine for my van in a matter of 2-3 weeks due to the 1st one being defective. Great luck I have. I trust my shop though and worked with them very closely to get it all squared away in the end, but I don't count out that they may have left something out cause I gave them a hell of a list of things to do while everything was apart.

Finally someone to confirm that removing the alt cable and the van dying means I could have a bad ground somewhere else!

How would I properly check the negative cable for resistance? Just put the voltmeter probes at both ends of the cable and see what I get?

Putting the voltmeter on the battery terminal negative post (I assume is what you meant by battery ground) and the other end on a good ground on the body won't blow the meter up in my face huh? lol

[searcherrr]

DAN !!! YOU GENIUS ! LOL
I just went out (remembered how to test) and tested resistance from ground mount to ground mount on the mounts and on the wires themselves in all the spots I could see. I wish I would've known about resistance testing before I put that cable from the alt to the frame cause now this is all coming back to me from when I did a bunch of this testing on my car.

The alt cable itself measures .5 ohm and from the alt body to the frame where its mounted is about .6-.7 but starts off initially at 1.7 till I press firmly. - As far as I'm concerned this cable needs to go. I thought it was still good, but apparently not. I'd rather have it closer to 0 ohm... at most a .3 ohm.

The real problem though seems to be right where you suggested to check at the battery negative cable. The negative THICKEST cable is actually perfect at 0 ohms, but when i measured the other two lil ones connected there the one closest to the driver side fender measures like 1.6 - 1.7 ohms. From remembering what a guy told me when I did this on my car anything over 1 is bad. DUDE !!!! THANKS FOR JARRING MA BRAIN!

At least now I know for sure that something was wrong here with the grounds and that my dropping resistor also is defunct. Perhaps these two things will yield me a FIX !!!!!!!! *$)_!*$)**** PERHAPS PERHAPS ! If it doesn't then at least thats something else out of the way and I can then focus on the O2's again or whatever else. I'm gonna price a new negative cable, but it would be nice if I could just fix it myself.

[LeSabre97mint]

I hope this thing runs for a very long time for you! I hope the ground problem fixes things for you!

Regards

Dan

[searcherrr]

Thanks Dan. I hope so too. lol - Its been quite a journey and I think I deserve some good long years of service out of this thing and I won't quit till I get to that status.

I was looking over the ground locations and my theory about the dropping resistor affecting idle may possibly hold water. Its directly off the main power distribution from the battery. The 2nd diagram is the stuff next down the power line.

[searcherrr]

I'm pretty pissed. My test results are skewed and I either did a lot of work for nothing or I still have an electrical problem.

I thought that it didn't matter which probe you used "WHERE" (red or black) when testing resistance??? When I test one way I get 0 ohms and the other way I now get 1.1 ohms. This is reduced from 1.7 and thats good n all, but still I was testing with the probes situated such that I got 0 ohms and was like HORRAAAY... and now I'm all pissed cause when I swap the probes I get the 1.1 still. I completely disassembled the negative crimped cable end with the 3 cables and redid it with a new battery terminal and thats how I got down to 1.1.

Only some of my testing in the last 5 minutes I did swapping probes so I don't know really what test results are accurate.

EDIT: Can you have a bad ground in the battery itself? I ask because it seemed like as soon as I connected the battery the resistance showed up at 1.1 and the cables themselves were 0 ohms when not connected. Though again I'm not sure about this "flip flop" the probes bit.

DUB-EDIT: Should I not be testing resistance with the battery connected? I was testing resistance with the positive cable still attached and the negative one detached then in the end I tested with both pos/neg cables attached.

TRI-EDIT: I was able to find my multimeter's user's manual online and it says to only test resistance with no power connected. Does that mean not only should I have removed the neg cable, but the pos cable too? When I did the tests with the battery connected I didn't do it for very long and nothing seemed to break or pop.

[wiswind]

You should check resistance with no power in the circuit.
Removing the negative battery cable should be fine.....

One thing that you should do.
Measure the resistance of your meter LEADS......
It is normal to see some very small amound of resistance......but it can be more if the leads are going bad.....or even with the connection between the leads and meter in the plug.
When you think you are getting funky readings......do a quick touch of the ends of the leads together for a sanity check.
I use a DMM all the time in my "day job".

Bad.....or intermittent grounds will cause all kinds of problems.
Some of those grounds.....particularly the negative battery cable carry a LOT of current......
A cable that carries a LOT of current can check out perfect....and fail under load.
For what they cost.......replace.

Batteries have a variety of ways to fail......so, yes....a connection issue there is possible......so that would be a place to look after verifying the ground......and while you are at it.......why not check the power connections?

With the engine changes.......and the age of the cables......worth a good check....as you are doing.
A cable that checks good....but has visible broken wire strands....etc.....should be repaired or replaced.

I cannot see why you would not be able to get at least 20-23mpg on the freeway.
This is going the speed limit.....with the cruise control.
As fuel becomes more expensive.....I have been trying to be more efficient with my '96.
Your '95 does not have the IMRC......which is a nice power boost....but is a MAJOR drain on fuel economy.
Performance and economy are opposite ends of the spectrum.
However......taking it easy will get you the MPG......once you get things resolved.

As I have mentioned.....and you mention above.....just replacing Oxygen sensors because they are old is not necessary.
They do slow down with age.
If they get too slow.....the OBDII system will light the CEL and have a code telling you that they are switching too slow.
I DID change my upstream oxygen sensors with Motorcraft ones......while they work just great.......I got no difference in performance or economy.
That was at about 160K+ miles....and they had slight green stains from the coolant leak at the lower intake manifold gaskets.

I'm also continuing to hang on to my windstar....as I only have to drive 10 minutes each way to work......fuel economy is not as critical....and I have use for the utility of the minivan.
It would cost me more to have a 2nd vehicle just for the fuel economy aspects.
Not having a car payment enables me to pay ahead on my mortgage....and pay cash for upgrades to the house.
Maybe even pay cash for my next vehicle.

I am hoping that you get the smooth running and economy aspects in line soon.

[searcherrr]

Lots of sanity checks. :2cen ts::2cents :

I have checked the resistance on the DMM recently, but for sanity I will do it again. Come to think of it now I do believe my "funky" readings may have only been when the negative cable was connected. At least now I know though "which" test mode is APPROPRIATE so that all future readings as long as the neg cable is removed will be cool.

I took apart and repaired, recrimped, and reterminaled the positive cable a long time ago. I resistance checked it too today and it seemed fine (this was for sure with the neg cable off).

I may go out in the drive way tonight and try these tests again so I can sleep better. lol

FYI on the Ypipe situation - Anyday now Magnaflow is going to send me shipping info so I can get the Ypipe thing squared away. I'd usually move on to another brand at this point, but I'll be returning the pipe to the seller for my money back and getting a free one from Magnaflow (their guinea pig) in return + my old pipe back as well. Hard to pass that up even though its gonna be a few weeks wait and after all I really did want Magnaflow brand cats. In any case the van will sit with tape over the exhaust manifolds till I get the new Ypipe back. Might be a good time to go buy a cover for the van cause its gonna go in the backyard till I get the new pipe.

Thanks Wiswind.