My 89 IROC has been giving me fits for the last couple months. When started cold, it runs like crap, very rough and stumbles and coughs through the intake. When it warms up it gets alot better but still hesitates a little and idles kinda rough. I ran injector cleaner through it and pulsed each injector and they all sound fine. I tried changing the IAT sensor,TPS, temp sensor, and distributer with no luck. Any advise on what to do next will be appreciated.

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2000 NHRA Edition T/A
Pewter Metallic
A4 3.23 Gear w/GSC's
Whisper lid, MAF Ends, Ram Air Kit, Exhaust C/O
Best 60ft:1.94
1/8th:8.381@86.03
1/4:12.963@108.44

1989 IROC-Z 5.7 Dual Cat
Auto w/3.27 gears
Jet Stage 2 chip
Modified Air Box&MAF
AFPR&Air Foil

Sounds like the O2 sensor is partly correcting the problem once it goes into closed loop. Hmmm... Have you tried changine the MAF sensor? Or you might just try unplugging it to see if that makes a difference.

[This message has been edited by ViciousZ (edited October 04, 2001).]

Tried unplugging it.... no good.... tried changing coils.... no good.... checked the plugs, all look ok. I'm ready to set it ablaze

I have a autotap for my Trans Am and was wondering if anyone makes something like that for a 3rd gen, something I can hook up to my laptop and check things out.

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2000 NHRA Edition T/A
Pewter Metallic
A4 3.23 Gear w/GSC's
Whisper lid, MAF Ends, Ram Air Kit, Exhaust C/O
Best 60ft:1.94
1/8th:8.381@86.03
1/4:12.963@108.44

1989 IROC-Z 5.7 Dual Cat
Auto w/3.27 gears
Jet Stage 2 chip
Modified Air Box&MAF
AFPR&Air Foil

Dano,
Hey you might want to check and see if you have a vacume leak. That could cause you all kinds of trouble, I had one and it made my car hard to start, and then would barley ide, but when it would warm would run alittle better. So I would start there.

Oh to anwser your other question you could get an auto xray and scan your car, it will let you know if you got any trouble codes, there right under 200 dollars.

Well hope this helps you out