Fuel Pressure Testing- how you doin it?

[roaniecowpony]

Have videos, contacting adm, getting an error message.

For vids, I just make a youtube on my account and post the link. Not sure how to post a video directly to the forum.

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[dstevens]

For the secondary o2s they should also go rich-lean then lean-rich but over a longer time period than the primary o2s. They also can stick lean or rich for some time, especially at idle.

What I see is that the both primary o2s are cycling in a reasonable time period and the fuel trims are pretty close to 0% and also fairly equal for each bank.

How is the idle now?

 

[azjl#3]

This is a great thread.

I am pretty sure it has closed loop but not enough time or temp to low so it remains open?

I mean closed loop has been a thing for 30 years

 

[azjl#3]

yeah just verified all EFI's since mid 90s have been closed loop including 3.6, and all other jeep

not going closed loop can be a result of many issues, cat, o2, wiring, fuel pump, filter, fuel quality, etc.

pretty sure the heated part is the bank 2 reading pretty stable, that heats the sensor

so on a guess, how old are batteries?

 

[Shellbird01]

Ok does this work?

 

[mwilk012]

Ok does this work?

Alright that’s all normal.

 

[mwilk012]

Do you have any more specific details on the surging itself? What are the fuel trims reading when it occurs? How rapid is it?

Didn’t you just have most of the engine torn apart recently?

 

[Shellbird01]

Ok, no sound….. will try again, this is the OBD with rpm Evap etc, wasn’t at its worst but what I could get this am. Kinda goes along with EVAP?

Going to look for exhaust leaks at cats, etc when resonator pipe arrives.

Could it be fuel / ethanol related?

 

[Shellbird01]

yeah just verified all EFI's since mid 90s have been closed loop including 3.6, and all other jeep

not going closed loop can be a result of many issues, cat, o2, wiring, fuel pump, filter, fuel quality, etc.

pretty sure the heated part is the bank 2 reading pretty stable, that heats the sensor

so on a guess, how old are batteries?

Sorry I didn’t see this post till now. About 2 years

 

[Shellbird01]

Exhaust leaks are done, the mis fires below happen during the reving, a leak down test next. could it be a stuck valve, maybe the inlet valve wold cause the popping noise in the air filter?

Tried a cam crank relearn, but wouldn’t finish. ,,,, PCM?

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