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

[searcherrr]

My old fuel injectors Ohm out as:

EDITED: to remove the k behind the numbers

14.7 ohms injector 4 -----front bank
14.5 ohms injector 5 -----front bank
14.5 ohms injector 6 -----front bank

14.5 ohms injector 1 -----rear bank
14.4 ohms injector 2 -----rear bank
14.3 ohms injector 3 -----rear bank

Does this tell me anything at all?

[Selectron]

Originally Posted by searcherrr

From what I read elsewhere and what you guys say I shouldn't see ANY voltage at all at the fuel injector harness connector with KOEO...

If you're measuring voltage directly across an injector pair - the red wire and the non-red wire - then that's correct, but as Wiswind said, you should read 12V on both wires when the meter's common (black) lead is connected to a known good ground elsewhere in the engine bay.

Originally Posted by searcherrr

... pressure should just hold and if it doesn't then 1 or more of the injectors must be getting voltage when it shouldn't be or that new injector may be bad

No, that isn't the way that it works. Each injector's red wire is intended to always have 12V available (with the ignition switch in the Start or Run position), so if an injector was being held open due to an electrical fault, the fault would be on the ground side of the circuit, and it would indicate that the non-red wire had a permanent short to ground, instead of just being switched to ground briefly by the PCM. Or it could indeed be a bad injector.

Originally Posted by searcherrr

I spent some time tonight looking up injector data and basically it doesn't appear that you test them for voltage, but that their resistance lowers the battery 12v voltage when its applied.

That's a pretty dodgy test and I'd just ignore it. It's a primitive way to indicate continuity through the injector's solenoid coil, but it's much better to measure that with a multimeter on the resistance range.

Speaking of resistance, your readings for the old injectors don't seem right - if that's around 14.5 ohms each then that sounds ok, but I wouldn't have been expecting kilohms.

I wouldn't be surprised if you're seeing anomalies in the injectors at the moment though, because the TPS is unplugged. The PCM uses inputs from several sources to determine the duration of the injector pulses, and the input from the TPS will be one of the more significant inputs, so if that's missing then it won't be too surprising if the injectors aren't behaving in the way you would expect, so I don't think that you necessarily have a new fault condition.

[wiswind]

Injector coil resistance will be 11 to 18 ohms....from the chart for 1996 that I am reading.
So your resistance is fine.

Things are looking up....we are off page 13.....so the jinx should be off.

I am betting that if the injector is leaking....that it would be some dirt on the valve seat.
One thing that you can do is put another injector into the leaking location......if a known good injector is leaking there....then you may have an issue.

I have had a LOT of trouble with misfire from dirty injectors, as I have mentioned before.
When an injector is not spraying due to dirt......the PCM is trying to compensate.....and everything is OFF......

[searcherrr]

I want to stop and thank Wiswind and 12Ounce and everyone else (tripletdaddy of course too) yet again. I really feel better with you all along this horrible journey of mine.

Hey Selectron. Thanks for coming back.

You were right about the "K" for ohms. I just edited my post. I had the digital multimeter set to K with ohm symbol, but the display only showed ohm symbol without the K when I tested again just now.

Injector Harnesses Test
I tested all 6 injector harnesses just now and made sure the black wire of my meter went to the ground wire of the 2 wire injector harnesses and the other probe (red) went to the VPWR wire of the injector harnesses.

Key On Engine OFF - Results are as follows:

EDITED: mV is correct; NOT "v" as was before. Also, since I remember from my photographic memory the location of the injectors that were measuring 11.8 I know it was 2 & 3 and not 5 & 6 since I keep confusing which bank is which.

5.43 mV Injector 4 -----front bank
5.50 mV Injector 5 -----front bank
5.48 mV Injector 6 -----front bank

5.59 mV Injector 1 -----rear bank
11.8 mV Injector 2 -----rear bank
11.8 mV Injector 3 -----rear bank

I forgot to test from the VPWR wire to a vehicle ground. Those tests were strictly from injector wire to injector wire using the injector harnesses only.

What do ya'll take from that?

What I take from it is that I have a short to ground on Injector 2 & 3 which makes sense since this is where I hear the constant squirting coming from with K.O.E.O., but what confuses me is that I have voltage AT ALL on any of the injector harnesses while the engine is OFF (yet key ON) and/or not CRANKING. I thought I shouldn't even see those 5.5mV readings??

Guess I need to test from VPWR wire on injector harnesses to ground too. I'll do that in a lil while.

Selectron - I found some reference values in my Ford CD-ROM (for the injectors) and they were in units of measure mS (millisiemens). The values were stated for KOEO, Hot Idle, 30mph, and 55mph. They are:

KOEO: 0 mS
Hot Idle: 5.7mS - 6mS
30 mph: 4.9mS - 7.9mS
55 mph: 6.8mS - 11.7mS

I used this conversion calculator: http://www.unitconversion.org/electr...onversion.html to convert mS to likely probable voltage that the injectors should be seeing. The problem is I don't know if this would be an accurate method for determining the right voltage for my application (the Windstar engine). Is that an accurate way to determine voltage from mS or no?

For voltages calculated/found using the mS values above, I came up with:

KOEO: 0mV
Hot Idle: .0057mV - .0060mV
30 mph: .0049mV - .0079mV
55 mph: .0068mV - .00117mV

So if I'm figuring all this stuff out right (for the first time ever) as I read that the injectors don't even require a whole VOLT to run the engine at hot idle?????

[wiswind]

I would NOT use the non-red lead at the injector to check voltage at the RED wire.....use a known good ground.

If you still see a super low voltage at the red wire on several of the injectors......measure again at the injector plug of the wire harness.....with the injector UNPLUGGED....
In other words.......secure the black lead to a known good ground.....unplug the connector from the injector and check the red lead.
If it is low with the injector plugged in.....and high with the injector unplugged.....then it is somehow being turned on.
If it is low with the injector plugged in AND unplugged.....you have a voltage supply problem.

Now.....you mentioned that the injector wiring harness was melted?.....For the cost (just over $36 plus shipping) I would replace it.
It is more likely that the harness melt is a problem than the PCM......not certain.....but it is a known issue......and (my favorite) it is cheaper.

With the motor running? You cannot rely on a meter reading at that point as the injectors are being pulsed.....so it would be a Oscilloscope viewed waveform.
If you have a leaker with the engine not running.....then there is no need to worry about looking at the run pulses.

[philkb]

Hopefully there is not a short to ground in the wiring harness for any of the injectors. If so, such injector is most likely TOAST!. As we know, they are only meant to be pulsed on for a few milliseconds at a time and if a continuous current flows through them the coils will certainly overheat and possibly cause the pintle to be jammed open.

Phil

[searcherrr]

Originally Posted by philkb

Hopefully there is not a short to ground in the wiring harness for any of the injectors. If so, such injector is most likely TOAST!. As we know, they are only meant to be pulsed on for a few milliseconds at a time and if a continuous current flows through them the coils will certainly overheat and possibly cause the pintle to be jammed open.

Phil

What if i only tested it with the KOEO a couple times less than like 30 seconds outside in the cold? I just wanna know if by testing them (2 & 3) for that short a period if I may have blown my new ones.

The new ones have not run in a running engine yet and my TPS and IAC are still unplugged as the rest of the intake is still off the top.

I'm going to continuity test the injector harness while its disconnected from the PCM harness.

I'm also gonna pull the cowl and continuity test the injector harness while plugged in to the PCM harness (PCM end) from the injector harness main connector site to the PCM as well as from the injectors to the PCM itself.

From what I see I think i'm going to find the injector harness itself is in good shape, but that the PCM harness (the one that is partially melted) is the problem.

I mean, isn't it obvious with injector 2 & 3 showing 11.8mV at KOEO that 2 & 3 are shorted to ground? Or is that not good enough to be concrete about it?

[searcherrr]

Originally Posted by wiswind

Injector coil resistance will be 11 to 18 ohms....from the chart for 1996 that I am reading.
So your resistance is fine.

Things are looking up....we are off page 13.....so the jinx should be off.

I am betting that if the injector is leaking....that it would be some dirt on the valve seat.
One thing that you can do is put another injector into the leaking location......if a known good injector is leaking there....then you may have an issue.

I have had a LOT of trouble with misfire from dirty injectors, as I have mentioned before.
When an injector is not spraying due to dirt......the PCM is trying to compensate.....and everything is OFF......

I don't know if I said it or not, but what I'm doing now is with newly installed injectors within the past few days. Intake is still off along with the IAC and TPS out of the loop. I only posted info on the OLD injectors for reference. So no dirt on the new injectors.

My OLD injectors are no longer installed. This constant squirting of fuel at KOEO is with the NEW injectors and I believe this was happening with the old ones too because I have always (since new engine install) noticed a little bit more than usual amount of white smoke out the tail pipe in the morning or after it sat for a while.

I guess things are looking up. lol - Its hard for me to be positive right now because I'm scared I'm going to find something else wrong that the shop did.

I have my settings displaying 20 posts per page so on my view here of the forum we're on page 11. lol - Maybe when MY view is past page 13 the jinx will go away.

Yeah, I thought about swapping out injectors to see if the squirting still happens in the same position, but I really don't think I need to since I know I have new injectors and I've so far seen voltages of near 12v at KOEO on inj 5 and inj 6. I'm about to post some other test results too.

[searcherrr]

I have to apologize to ya'll. A lot (or most) of these posts come in during the weee weee weeee hours of the morning... late late late... and I think I've screwed up a few details. I'm gonna go back over the last 2 pages of posts and make sure I got things right (mostly for test results). For some reason even though I've marked things well in the engine I cannot seem to absorb that the 1,2,3 cylinders are in the back and 4,5,6 in the front.

I think I kept saying 5 & 6 were the ones with the higher voltages, but at the same time I said they were in the rear bank... which is incorrect. I distinctly remember testing those near 12v results in the rear most right two (closest to driver wheel) cylinders which are 1 & 2.

I realized I'd made this mistake tonight when I went out in the cold to test some more stuff. So I'm gonna go EDIT a couple things and then post some new test results too. My new test results are confusing me even more.

I'm starting to wonder if shoving paper clips in and out of the connectors has cleaned off the connector surfaces thus changing the test results..... OR handling the harnesses and bending/twisting/jiggling them etc... may have changed the results cause I did the same voltage tests tonight (in addition to others) and got different answers than the other day.

[searcherrr]

Originally Posted by wiswind

"Waiting for mosquitoes to subside".....I have to do a double take when I read that......not an issue on a February evening in Wisconsin.

I would think that your motor would run rough with wires 5&6 crossed.......
Now 5&1 or 6&2 crossed, would not matter as they are on the same coils......and fire together anyhow.

I thought on my 95 the pairing of the ignition coils goes like this: 1&6, 5&2, 4&3

I'm assuming "pairing" works that each coil set is directly across from the other, measuring/looking across the shortest width of the coil pack.

[Selectron]

Originally Posted by searcherrr

I found some reference values in my Ford CD-ROM (for the injectors) and they were in units of measure mS (millisiemens).

Nope, the S isn't referring to Siemens (the standard unit of electrical conductance), but instead it refers to the second (standard unit of time). Thus the figures you're seeing in the manual are the pulse durations for the fuel injector measured in milliseconds (mS).

The figure which you quoted of 0 milliseconds for KOEO is handy, because that confirms that the injectors should indeed remain switched off at that point, which is what we'd all pretty much agreed on. Then at hot idle you've quoted around 6 milliseconds, which sounds perfectly reasonable. Then of course if you were driving the vehicle, as you accelerated up through 20mph, 30 mph, 40 mph, the pulse duration would keep gradually increasing in order to allow greater fuel flow in order to attain those speeds. It's often spoken of in terms of 'duty cycle', with the duty cycle increasing at higher speeds, decreasing at lower speeds, and falling to zero at KOEO.

Just to clarify on the subject of the injector operating voltage - it is always 12V (nominal), and flow rate is adjusted not by varying the voltage, but rather by varying the length of time (pulse duration) for which the injector is held in the 'open' position.

At KOEO, no current should flow through the injectors, but if you have an electrical problem which is causing one or more to be held open, then current flow through an individual injector will be around 0.8 amps (12V divided by 14.5 ohms), with a power dissipation of around 10 watts (12V multiplied by 0.8 amps) - that's far too much heat to be dissipated continuously in such a small, unventilated component, so don't leave the ignition switched on for any longer than necessary whilst you're taking voltage measurements, and do allow an interval for cooling between taking sets of measurements.

Do as Wiswind said when measuring voltages - connect the meter common lead to a known good ground, and measure the voltage first on the red wire and then on the non-red wire. No need to measure the voltage directly across the red and non-red wires, because we can derive that later, by subtracting the non-red voltage from the red voltage.

You said you've discovered anomalies in your voltage readings, so I won't comment on those until you've clarified them.

[searcherrr]

This post for corrections only:
From post 191 up till this one check for BOLD and RED corrections I've made to my posts.

[searcherrr]

Originally Posted by Selectron

Nope, the S isn't referring to Siemens (the standard unit of electrical conductance), but instead it refers to the second (standard unit of time). Thus the figures you're seeing in the manual are the pulse durations for the fuel injector measured in milliseconds (mS).

You are definitely much more an expert on the electrical stuff than me, so I don't want this to seem like I'm arguing. I merely want to be VERY sure on this unit of measure because I researched the "mS" notation before doing all that stuff I did in prior posts.

What I've found is that:
lowercase notation: "ms" = milliseconds
and
lower/uppercase "mS" = millisiemens

In the reference value chart I found it shows as lower/uppercase "mS" specifically.

I looked it up here on these sites:
http://en.wikipedia.org/wiki/MS
http://www.sizes.com/units/symbol/mSmn.htm
http://inst.sfcollege.edu/mugs/DRC/U...IC%20CHAP2.txt
http://www.translatorscafe.com/cafe/...conductance/c/
http://www.translatorscafe.com/cafe/...verter/time/c/

I debated with myself too about milliseconds vs millisiemens. In any case whether we are dealing with TIME or AMPERAGE/VOLTS zero is zero for KOEO.

Originally Posted by Selectron

Just to clarify on the subject of the injector operating voltage - it is always 12V (nominal), and flow rate is adjusted not by varying the voltage, but rather by varying the length of time (pulse duration) for which the injector is held in the 'open' position.

Got it.

Originally Posted by Selectron

At KOEO, no current should flow through the injectors, but if you have an electrical problem which is causing one or more to be held open, then current flow through an individual injector will be around 0.8 amps (12V divided by 14.5 ohms), with a power dissipation of around 10 watts (12V multiplied by 0.8 amps) - that's far too much heat to be dissipated continuously in such a small, unventilated component, so don't leave the ignition switched on for any longer than necessary whilst you're taking voltage measurements, and do allow an interval for cooling between taking sets of measurements.

I've decided I see no reason to leave the injectors plugged into their harnesses until I've isolated the electrical fault, so they are unplugged for now.

Originally Posted by Selectron

Do as Wiswind said when measuring voltages - connect the meter common lead to a known good ground, and measure the voltage first on the red wire and then on the non-red wire. No need to measure the voltage directly across the red and non-red wires, because we can derive that later, by subtracting the non-red voltage from the red voltage.

Coming up in next post. I did this earlier. Just didn't get time to post it till now.

Originally Posted by Selectron

You said you've discovered anomalies in your voltage readings, so I won't comment on those until you've clarified them.

Yes, but its been hard keeping track of all this ... retracing errors I made myself and things that happened that I'm doing a double take on. You see in next post.

[searcherrr]

EDIT: I had written quite a bit on millisiemens calculations, but a google search for that term and fuel injectors comes up with zilch so my Ford Cd-ROM must've notated "mS" improperly and was meant to be "ms" cause "m uppercase S" is millisiemens though from what Selectron said and reading up on injector stuff milliseconds is the appropriate word.

Reference Values from the FORD CD-ROM (I accidentally found these):

ms = milliseconds
KOEO: 0 ms
Hot Idle: 5.7ms - 6ms
30 mph: 4.9ms - 7.9ms
55 mph: 6.8ms - 11.7ms

Here are the previous test results I posted earlier:

Tested Injector Wire to Injector Wire - 1st Test
5.43 mV or .00543 volt - Injector 4 -front bank
5.50 mV or .00550 volt - Injector 5 -front bank
5.48 mV or .00548 volt - Injector 6 -front bank

5.59 mV or .00559 volt - Injector 1 -rear bank
11.8 mV or .01180 volt - Injector 2 -rear bank
11.8 mV or .01180 volt - Injector 3 -rear bank

Now for what I did last night:

Tested Injector Wire to Injector Wire - 2nd Test

Same as 1st test results except the 11.8 mV was missing from injectors 2 & 3 and instead was around 5.5mV like the others. ODD???


Tested Injector Wires to Chassis Ground - 3rd Test

3.3 mV | Injector 4 -front bank - red wire
Nothing | Injector 4 -front bank - non-red wire
3.0 mV | Injector 5 -front bank - red wire
Nothing | Injector 5 -front bank - non-red wire
2.8 mV | Injector 6 -front bank - red wire
3.3v - 6.0v | Injector 6 -front bank - non-red wire

3.2 mV | Injector 1 -rear bank - red wire
Nothing | Injector 1 -rear bank - non-red wire
3.2 mV | Injector 2 -rear bank - red wire
Nothing | Injector 2 -rear bank - non-red wire
4.0 - 3.2 (settled at 3.2) mV | Injector 3 -rear bank - red wire
Nothing | Injector 3 -rear bank - non-red wire


Continuity testing of entire Injector Harness while unplugged from PCM - 4th test
All continuity tests passed with zero resistance.

This leaves the continuity tests from the male ended injector harness connector on the PCM side to the PCM connector (gotta remove that dang cowl).

Ok ironing things out:
1. Even though I'm going crazy with all this I know injectors 2 & 3 showed 11.8mV or 11.8v the 1st time I checked KOEO red injector wire to non-red injector wire. Problem is since I screwed up the mV vs V thing I can't recall which (mV or V) it was for sure.

2. I should be getting NOTHING for the red wire's against chassis ground right? Whats up with this mV stuff I'm seeing?

3. Why did injector 6's non-red wire give me a mV results against chassis ground?

4. Perhaps in twisting, moving, the injector wiring harness I've caused some shorts that were revealing themselves to go away? or vice versa?

5. I shouldn't be seeing "ANY" voltage at all (even mV) off those red wires with KOEO...... but given the resistance of the injectors between 11.0 and 18.0 ohms (haven't measured the new ones; but old ones were 14.5 ohms on average) would a mere 3.2mV to 5.5mV of voltage even cause an injector to open at all going against say 14.5 ohms of resistance? IE: .0055v / 14.5 = 0.000379310345 amp .... looks like nearly zero current flow to me equating to likely zero injector opening huh?

6. Lastly - Anything that looked odd I repeated the test for several times before writing it down.

[searcherrr]

I think continuity testing to the PCM from the injectors and from PCM injector pins to chassis ground is gonna show me what I'm looking for. Its gotta be some trickle current getting in somewhere.