I have a code 42, and for all intensive purposes my 2.8 has an adjustable fuel pressure regulator, the engine is modified.
ideas?
leaking injector?
mis-adjusted fuel pressure regulator?
bad throttle position sensor?

the engine stumbles with the slightest throttle input anywhere under 2k, any rpm higher than that and the throttle response is fine.
I think the tps is sending the incorrect throttle input and is telling the ecm that the throttle input is greater than what it actually is.

engine does not fire right off, like it should, during a cold start. maybe my timing is off? (last time I set it, all cylinders were even at 11*btdc)

I have a 3.4 exhibiting the same low rpm problem. However, mine starts on the first crank. I have replaced the TPS with no change. My regulator is stock. I need to check it. Apparently they can leak and cause drivability issues.

[This message has been edited by Rick 88 (edited 11-07-2013).]

I just replaced the TPS and IAC valve,
I checked and reset the timing (was 12* btdc and I set it back to 10)
I'm resetting the idle now and will drive it later and pay attention for any noticable improvements.

I disconnected the battery, so everything will be reset. wish me luck! XD

[This message has been edited by AL87 (edited 11-08-2013).]

I believe I had a code 42 a while ago and did some tests of a few things and found after pulling the distributer cap that the pickup coils protective coating had started to disappear. I pulled the distributer and changed it and that was the end of that.

now I say always test never just replace parts at random because it can get very costly. but if you see the coating starting to disappear around the pickup coil and an intermittent check engine light when the engine starts to run like crap chances are that could be your problem.

Edit to add, it could have been code 43, my memory is shot and it was last year or the year before.

Steve

------------------
Technology is great when it works,
and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

[This message has been edited by 84fiero123 (edited 11-08-2013).]