I am starting to think it is an intermittent problem with the iac. Whatever it is is back and forth. I know the ATF was run through it so that may have caused some type of issue. Will change it soon.

Had to work on my everyday car today, Ford focus alternator and thermostat. Really would like to meet the engineer that designed that set-up. Took all day but at least I can drive again.

 

Ok back to the grind. New IAC and initially it is idling better. Holding the idle better. Once it starts to move it will stall. Drove it short distance around neighborhood and it was surging. Such as it would be turning 2500rpm and like a switch was flipped it felt like it was out of gas or spark, then back on again. I think the iac was part of the problem with the idle surging.

Now I think I should be looking at the TPS, CPS, ICM and or MAF again. Maybe other issue where masking the new MAF's that I tried earlier. Thoughts?


EDIT I did test TPS with the meter. Under 1v on idle and seems to transition up and down smoothly. Checked it engine off and it went to five and back down nicely. Not sure how it's suppose to work engine on, but it seems like the values with the engine running don't correspond to that with it off. Such as engine off with throttle body advanced so far may read 3v, with the engine on idle in the same place reading may be 2v.


Also have good fuel pressure and I did a flow test to be sure. At idle it pumps about 1 quart in 30 seconds, which seems correct.

 

When my 87 was pinging & stalling off the line I scanned it and got a 53 "TPS voltage to high."

Checked the output voltage and it was jumping all over the place.

Your TPS looks good.

Have you scanned it again?

 

I will scan it again. I did test output voltage and it looked good, but I have also seen them test good and still be bad.

 

I am not very good with this computer stuff so please stay with me. I got some video of MAF voltages so I am thinking I am going to try another one and see where that takes me. I think there are multiple issues that have made diagnosis a pain. When I put new MAF on atf was being poured in. The new MAF voltages where high but may be the computer needed to "learn" them. if this was a carb engine I would think it was a intermittent fuel issue, I'm just not sure what sensors can shut an engine down.

If the resolution is to high let me know and I'll try to lower it and repost. I am under the assumption that if a new MAF shows the same voltages then the pcm is faulty. Thoughts?

Is there anything besides the the MAF or PCM that can cause something like this? Will a vacuum leak cause this? I had read that a leak would cause a MAF code, but would it behave like this? Thanks.

Erratic MAF signal Engine Running
Pogoplug: 20150812_091800.mp4




Key on Engine off Signal
Pogoplug: 20150812_095051.mp4




Engine running then stall
Pogoplug: 20150812_095407.mp4




My favorite. MAF voltage finally correct on idle the then rises and stalls
Pogoplug: 20150812_095448.mp4

 

Also wanted to ask if a leaking injector could cause something similar. Such that is the engine is trying to balance an air/fuel ratio. If it is getting more fuel the iac could be opening up to maintain idle thus causing the MAF to create higher voltage because of the increased air flow from the IAC opening?

 

If you checked fuel pressure and it did'nt leak down with the engine turned off you dont have a leaky injector.

My cp9087 has complete instructions for testing the MAF & it's circuit.

Under the heading test MAF signal wire for short to ground

Key off connect yellow test lead to MAF signal pin. Connect black test lead to good vehicle ground.
Good circuit test light on in any position
Bad circuit test light off

Converting that to your ohm meter it looks like you should see some amount of resistance from the computer, but if you see a dead short thats a problem.

Why a short to ground would'nt light up the CP9087 is a mystery to me.

 

I did test the MAF signal and ground from the sensor to the computer and they were fine. I am going to replace it with another one this week, and see what that does. None of the MAF's made a difference earlier, but that was before I found the atf leak. It was hard to test them with the truck running because it kept dying. So i'll see if that will help. These guys at the parts store are going start wondering what I am doing with all these MAFS.


Thanks

 

Are you buying reman MAF sensors????

 

The first one was because it is what they had in stock (had ford stamped on it), the second was new. I am really starting to think the MAF is bad as it shows in the videos, and when I originally switched them out the ATF was still causing it to run like crap, and I thought the problem was unresolved. I don't remember the readings being erratic, just high. That could also be do to the O2 sensors reading lean and adjusting the fuel trim to put more fuel in it.

I have a new MAF on order so we will see. I also did a vacuum test today with a gauge while I am waiting on MAF and all that was good so I can eliminate a lot with that, emissions, leaks, etc...


If the new MAF is all over the place like this one, then I am going to look at the PCM, and go from there.

I'm starting to think the blinking CEL (when I was pulling codes) was Morse for push me in the river.

 

Ok, good feedback. The blinking CEL is saying the computer is detecting cylinder misfire & that's not good for the cat converter. How much tranny fluid got sucked through the modulator diaphragm, as the phos in tranny fluid can take the cat converter out & sure won't do the O2 sensors any good either.

 

Blinking when I was pulling codes, after jumping wires with paper clip.

No telling how much fluid, truck is new to me and PO drove it for some time acting up. Could have done it for years or may have just started. If cat was clogged it should have shown in vacuum test. I bought new O2 but haven't installed yet, because I would like to see what this is before I change them out. I have never seen bad 02 cause these symptoms.

 

Ok. Got new MAF part of the issue but not all of it. The new one hold a consistent voltage and isn't all over the place. However it still dies at idle and under load. I believe my problem is going to be with the fuel pump or injectors. If it is not that then I will be leaning towards pcm. Any recommendations on manufactures injectors and pump. I am thinking I am going to start with the pump first.


Edit: Found this interesting, I unplugged and plugged the vacuum line to the FPR, to raise the pressure. Truck ran better with the higher pressure, so I am really thinking it is the fuel pump. Also on a side note unplugging that line directly effected the MAF. The MAF signal was high around 2v when I unplugged the vacuum it went down to 1.2v. So i am assuming a weak pump will effect MAF signal. if injectors are not getting proper flow, even though I thought flow check was good. We'll see.

 

Did you remove the battery B- cable to wipe the corrupt KAM fuel trim tables after installing the new MAF & IAC????
Post up the KOEO & KOER fuel pressure figures with the vacuum line attached & disconnected & the flow rate over time, it should be something like half a pint in 15 seconds. EDIT: Was the FPR vacuum line Dry inside/not wet with fuel???
Attach your fuel pressure gauge & inductive timing light to any plug wire & position the light & gauge so you can see them from the cab & watch to see if its spark or fuel delivery that's going missing when it stalls at under load throttle up.
Not sure yet what to make of your TPS voltage readings, were they made by back probing with your multimeter, or with a scantool????
Have you checked B+ under load & at various rpm, to make sure the alternator & battery output are up to snuff, so that you know for sure the computer & sensors are getting the specified operating voltage???
EDIT: After the battery disconnect/KAM wipe & another stall at throttle up, re-scan the computer & post All code Number clues.

 

Will do all reading are with multimeter (eec-iv). Battery was disconnected for some time. Fuel pressure is around 32psi and 40 psi with line unhooked, however it will slowly drop once engine is off, either check valve or injector. Did clear flood routine and nothing, so check valve in fuel pump. The MAf readings are what changed with the pressure. No fuel from fpr and it is a new motorcraft one.

I have done flow test using the return line on the fpr and before the fpr using the flow thing on the gauge, both times 1 quart in 30 seconds. I found some injectors for $90 for (6) and fuel pump with sender at orielly's is $82 and my sending unit is already not working. The battery is new but checked voltage all good there with battery and alternator. Also cleaned all connections and cleaned connections on power distribution box.

I will disconnect battery and see if I can get another code. I am fairly certain it is fuel in some shape or form. I may go ahead and replace tps even though all reading have been good testing it, I still suspect some type of intermittent issue with it.

My plans are
Tps
Fuel Pump
Injectors
PCM

In that order. If that doesn't work it should make a nice brim bed lol.


I will try the light and fuel pressure, although I have had it stall with no change in fuel pressure.