Engine Performance problem
1998 Isuzu Trooper 6 cyl Four Wheel Drive Automatic 117000 miles
I have a 98 trooper 4x4 3.5l v6 DOHC 24 valve. I had a IACV go bad with a check engine light about 3-4 months ago took it to PEP boys determined it was an IACV and replaced it problem solved or so I thought. Last week out of the blue the engine started idling fast at rest even after warming up, just like before when the IACV went bad. The check engine light comes on and goes off intermittenly. While driving it occasionaly gives out and then surges and sometimes stutters especially when just cruising at steady speed. I took it back to pep boys again due to being under warranty for The IACV and they said everything pointed to bad IAC they replaced it and took out drove it to let the computer reprogram the IACV and 10 minutes later same issue. So I took my trooper and went home and though maybe it was the brand of IACV they were using ( Warner) so I went to NAPA and bought a Echlin IAVC and installed making sure it didn't extend more than the recommended 1 1/8 inch into throtle body. I then took it out on highway and drove it for at least 20 miles @ 55 mph to allow the computer to reprogram it. And the problem still exists. So thus it leads me to believe that it is not an IACV but something else. Nothing else seems to be wrong other than my 4x4 wont work front axle wont engage I think its either electrical or vaccum in nature dont know if it is related. The other issue I know is wrong is my muffler and tailpipe I wasnt sure if this was somehow messing up my O2 sensors and thus causing problems for my IACV etc etc, Can someone help please? P.S I plan to replace the entire exhaust in March including both O2 sensors.
Saturday, February 20th, 2010 AT 10:29 AM