Jing

High idle/RPM drops very slow
<HR style="BACKGROUND-COLOR: #000000; COLOR: #000000" SIZE=1><!-- / icon and title --><!-- message -->2002 Cavalier Z24

I have tested the O2, maf, and we have tested coolent sensor... I have also checked the throttle springs to ensure it wasn't holding it back...
When driving, and you get the engine to say 4,000 RPM it randomly locks at that rev while shifting up... if you press the excellerator while the clutch is in it will go to say 4500 and lock there... and you basically have to ride the clutch to have it drop the RPM... no codes are thrown at all. the only thing i have not tested is the actual computer controller...

the engine does idle at 1500 RPM now when before it was idling at 900 - 1000... pulling the MAF censor off it drops the idle to the correct lvl but runs like crap :P we have tested the censor on another cavalier of the same model and it runs fine so i know the censors are fine.

EinST

I suppose the devil is in the details. How did you test the sensors? Wiring? A lot of sensors are susceptible to resistance changes in the wiring. Vacuum leaks? If the problem could be easily repeated, have you had it checked out at a shop?

Jing

My father is a lisenced machanic for 33 years as well as an avionics tech... he also runs his own transmission shop ATM... he has tested the sensors... i'm not an expert by any means but i have been told that they work just fine... we have not yet had time to check for vacuume leaks or the wiring... which i guess is my next step on my days off... only other thing is the ECU or whatever the abriviations are for the computer

teh issue is not easily repeated... like i mentioned it is "random" and varies when the car is cold vs warm... about 95%of the time the RPM just drops extremly slow when you are shifting up...

any other Idea's would be helpful

EinST

It sounds like you and your father have a plan of attack and enough resources, then. Good luck.

Jing

i have taken it to a GM shop and had them check it... they charged me over $300 to check it with their computer only to find no codes that had been thrown... and told me that nothing was wrong with it...