:o I have a 88 Iroc with 5.0 tuned port injection it wont idle down and is running rough and rich.

I would guess it the ox sensers... Or and intake/vacuum leak

idle increase usually indicates a vaccum leak. however with the computer age, who knows. does it have a mass air flow sensor, did anyone try to unhook any of the polution especially the pipe that runs down to the converter from the intake, smog pumps etc. you either have to strip it to bare bones and put aftermarked intakes etc. or leave the orginal alone. vac leak 1st guess, smog 2nd, computer items 3rd. good luck

I have a 88 Iroc camaro with tuned port injection and a five speed trans I came out of work and the car was hard to start (took alot of cranking on the starter) and when it did start it was running very rough and rich and will not idle down. I droped the codes and I am not getting any trouble codes.

Djd fixed it - merged threads...

DON'T ANSWER HERE :noway:

Double post - http://www.camaros.net/forums/showthread.php?t=152256

PLEASE - don't double post questions :sad:

I merged both threads so this is the one to answer in if you think you can help Phil out...

I merged both threads so this is the one to answer in if you think you can help Phil out...


Okay, since you fixed the double ;)

1.) As stated above, check for vacuum leaks - including EGR Valve, known to get stuck open...

2.) Check fuel pressure and regulator function - regulator may be aloowing high pressure at low vacumm levels (see above)

3.) Check IAC circuit - make sure solenoid is working correctly. It is effected by engine temp., so check the ECM temp. sensor. (outside chance a sensor failed so quickly, it should be a fairly easy trace by reading sensor)

High idle could be stuck IAC, running rich could be the ECM trying to compensate for the lean condition.

MAF can reek havoc also,...wait, 87 was speed density and 90 is MAF, correct? I forget...
Im too old to remember this stuff. I wanted to read this incase my 90 IROC-Z ever acted up.

I would check IAC first. I had the exact same problem with mine. It turns out it was the IAC