1995 Monte Carlo Z34 with rough idle problem.?

#1 (**permalink**) 11-23-2008, 06:12 AM

I have a 1995 Monte Carlo Z34 with a 3.4L motor and am having problems with starting it in the morning. The idle surges up and down and then about three minutes later it seems to even out. I have changed the oxygen sensor, the MAF sensor, the IAC sensor, and have had no luck. Anybody out there with any ideas?

#2 (**permalink**) 11-23-2008, 06:12 AM

When you changed the other parts did you reset the computer settings for the new parts? You can reset it by taking the ground cable off the battery, wait for three minutes and put it back on.
If it still dose this reset the timing by 2 degrees forward. This will help on cold starts.

#3 (**permalink**) 11-23-2008, 06:12 AM

It's the IAC just dialing itself in .If it smooths it self out leave it alone If the idle stays rough check for a vacuum leak . Check the TPS voltage .It should be around .5 volt ( Half of a volt) at idle .If you need to set the idle then start the engine and wait until it warms up .With engine idling unhook the IAC and set your idle. Then plug it back in and check the TPS voltage If you don't do this the IAC will try to compensate