Rough Idle

[johnb232323]

I have a 98' grande prix gtp. The engine has had a rough idle for the last 6 months or so. It does not seem to effect power once you hit the road. The tack needle also shows no movement when you are driving down the road, it is steady. When at idle it is bouncing between 800rpm and 1000rpm. The funny thing is that this is not always the case, at times it idles at 800 perfect. I also notice that when the AC is on it has no problems. I have changed the plugs and wires hoping that would solve the problem, it did not. If anyone has any ideas it would be very valued. Thanks

[richtazz]

Have you noticed any other electircal gremlins (loss of blower speeds, DIC flashing on and off, trac off light coming on)?

[johnb232323]

No other problems at all, thats why im having a hard time figuring it out. Some did say to try and remove an air sensor and clean it and see what happens...

[BNaylor]

Originally Posted by johnb232323

No other problems at all, thats why im having a hard time figuring it out. Some did say to try and remove an air sensor and clean it and see what happens...

I recommended removing the idle air controller (IAC) located on the throttle body. Clean the spring loaded pintle with carb or throttle body spray cleaner. Also, clean the IAC seat where it sits at the throttle body. Normally there will be a lot of soft carbon.

Also, won't hurt to clean the complete throttle body and the MAF sensor. Use electrical contact cleaner or MAF spray cleaner on the MAF hot wire element. Also, make sure the throttle body inlet screen is installed.

Note: Remove MAF sensor before cleaning the TB. Do not get carb or TB cleaner on it.

[johnb232323]

Okay, I'll give that a try, thanks for the info.