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Discussion Starter #23
So the bulb wasn't bad but the circuit was not complete. The two plugs that go into the instrument cluster, the printed circuit board part, several of the metal contacts had come unglued and bent out of place not making contact. Someone had been in there before as several mounting tabs for the bezel were broken. I need to super glue them in place and put some dialectric grease on them but for now I just got them positioned where they're making contact to ensure that was the problem, and the battery light is now coming on and it is charging fine. Initially was putting out 14.7v and now around 14.4v but the efan is on so thats probably why it's slightly lower I assume.

After this, I let it warm up and it actually didn't smooth out like it had been. It actually ended up stalling. I then restarted it and it was smooth. I checked the O2 sensor voltages and they are oscillating above and below 0.5v like you said. I pulled the vacuum line to the brake booster and checked them and the left stuck at 0.04v and the right at 0.00v. Plugged the booster back and they went back to oscillating. I'm wondering now if this charging issue could have been the whole issue, effecting the other electronics. Wondering now if I let it run a while and learn new long term fuel trims if it's going to run ok...thoughts?
 

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possible

or you could erase the KAM memory by disconnecting the batter neg for 10 mins

02s are voltage generators, they make that voltage you see

so battery is no matter, only the heater would be affected

sounds like most of your issues will be circuit/wiring issues
 

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Discussion Starter #25
Charging issue seems resolved. Battery light comes on every time and voltage is holding above 14v all the time. I let the car cool off, unplugged neg battery cable for 15 minutes, then fired it up and it was the same, still stumbling. What do you suggest I look at next?

Thanks
 

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drive it for while, and check for 02 codes

back probe maf signal at ecm while at warm idle

what do you read?
 

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Discussion Starter #27
ok will do. might be able to check tomorrow. I don't really drive it hardly at all, it's not my car. I have just been driving it around the block when I do drive it to test things out(I did today). It's a 3 mile loop, not very long. I'll try to drive it a few more miles tomorrow after it's warmed up, then check codes, and check maf sensor voltage.
 

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Discussion Starter #28
Ok, drove it about 10-15 minutes today. When it was cold, the MAF signal at ecm was ~1.2volts with slight variation, but pretty stable. Once warm at idle it was ~0.8volts with slight variation, but pretty stable. Tapping the gas it jumped up as expected, it appears to be rising/falling with airflow.
 

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rpm at the voltage?

higher voltage was the higher rpm?
 

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Discussion Starter #30
I'd have to double check exact warm idle rpm, but I think I set it right around 700ish. Yes, higher rpm = higher voltage. A quick light tap of the throttle brought it closer to 2 volts.
 

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you cannot set idle speed with the throttle stop

Idle rpm is set in the ecm, and changes all the time

so what do you mean you set it at 700rpm, you have a tuning device?
 
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Discussion Starter #32
Sorry, no, I followed the procedure listed online to reset base idle, etc. I reset base idle with IAC unplugged, I believe I set it around 600rpm or whatever the procedure said. Then plugged in IAC and let it run for a couple minutes without load then with load, or whatever it said to do. May not even matter, but that's what I read so I did it. I'll check next time I run it, but it's idling right around 700 rpm fully warm with no load.
 

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if its all stock, it may work

at this time we have probably exhausted all simple tool diagnosis

you say that this heat related, only has an issue during cold start and cold run

when cold you could try adding a fuel, like combustion chamber cleaner or brake clean, NOT ETHER, and see if the miss goes, then you would know it is fuel/air related

it may have an air leak that seals up when it warms up......possible

i think you are now entering the territory where more sophisticated tools are needed

a o-scope

need to look at secondary ignition wave forms, at the very least, this may give insight to what is happening in the combustion chamber when cold

I suggest you find a good diagnostic shop, not a mechanic, that has the right tools
 

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Discussion Starter #34
Do you mean to check for vacuum leaks, or to spray it into the intake tract? I have tried spraying brake clean all over looking for vacuum leaks and could not find any.

If there was a vacuum leak, would the idle stay steady, just high? This has a stumble to it...

Just to double check, is it possible the egr being deleted could have an effect on cold start/cold run performance? Would the ecm programming maybe cause this, with the egr completely disconnected and removed and blocked off, and the electrical connector disconnected?

Is it possible piston rings could be not sealing cold but when warm sealing? Like a dead cylinder when cold? I have not done compression or leak down test. Also thought about trying to smoke test the intake to check more definitively for leaks...

It seems very strange that the car runs like a brand new car when warm, but terrible when cold. I've never seen anything like this.

I appreciate all your help.
 

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spray fuel into the throttle body, during cold start

the air leak can be on the under side of the runner, where any spray will not reach

the egr blocked off will not cause this, if produces a code, egr will be disabled

in a maf car, an air leak will cause a lower idle, and when cold will cause a lean condition, lean during cold running , will cause stumbling

if you take temp of each primary, or unplug each plug wire and look for a non contributing hole you might be able to find if there is a dead cylinder when cold
 

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Discussion Starter #36
Im starting to wonder if there's something wrong with the ecm. The car is doing some strange things. Many of the gauge cluster components have intermittently not worked. Seat belt light and chime intermittently not working. The tach, volt meter, oil psi gauge, etc all have had a few issues while I was pulling and reinstalling the cluster due to the battery light issue. I thought it was those damaged contacts at the plugs, but after tinkering for a while they all seem to work except that seat belt light and chime have a mind of their own, and their contacts didn't even appear to have any damage. I've seen some people online who have opened up their ecm and found cracked solder joints, etc. that caused strange issues. I'm going to take a look for anything obvious.

I did smoke test the intake today and only found one very tiny leak at the pcv on the back of the intake. With the engine running, though, it is not leaking (I sprayed it running). It must only have leaked with the smoke test due to being under some positive pressure. Might do a cold compression check then try to isolate down to a certain cylinder like you suggested before I give up...
 

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you dont call the ecm, based on weird things

its obvious you also have wiring issues.......the ecm only has the CEL light connected at the cluster

the seat belt light does is NOT part of the ecm circuits

compression test will NOT reveal an air leak in the intake runner, intake lower to head or lower to upper

if the leak is in the valley you are not going to see it easily and obviously you are not going to be spraying anything there
 

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Discussion Starter #38
Thanks for the info.

I meant a compression test to see if a cylinder was down on compression, not for testing intake leaks. I'm wondering if there's a mechanical issue with the engine, only when cold. Not likely, I know, but I'm about out of ideas. Is there any other type of control module associated with fueling or ignition separate from the ECM? I'm wondering if one could be acting up only when cold? Even if so, this is probably beyond my troubleshooting capabilities...

I smoke tested the intake. I plugged the intake tube where it meets the MAF/air cleaner assembly, propped the throttle open, and filled with smoke from the PCV hose (Fresh air inlet hose to valve cover). I would think that I would have seen an intake leak even in the valley during the smoke test? I only saw a very small amount of smoke coming from the PCV grommet at the back of the intake. But under vacuum, while running at idle, spraying that grommet did not change rpm so I don't believe it's leaking under vacuum.
 

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options

-tear it down, and verify base engine is sound

-take it to a diagnostic shop that has the expensive tools to test with

i could diag if the car was in front of me, but it aint

i suspect it is lean during cold start and warm up

only could be verified by looking at long term fuel trims
 

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You know the PCV valve is closed when the engine isn’t running? Depending on how much pressure you used to force the smoke into the PCV inlet, it may not have made it into the intake system.
Suggest you run the smoke test again using something like the brake booster line or the vacuum tree feed.

-stuck EGR valve or maybe the ECT sensor is out of spec are a few other items for you to check.
 
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