1997 Grand Am GT 2.4 Rough Idle Please Help

[nebula72]

Hello,

First poster here :)

My name is Tom and I have a 97 Grand Am GT with a 2.4 that has a rough idle. Currently not thowing any codes. Here is what I've done so far:

New Plugs.
New Coils including the white plastic piece which connects to the plugs..
New Fuel/Air Filters:
Cleaned out TB/injectors.
(Was told by service tech that O2 sensors are fine.)

When the car is at driving speed, the car seems to run fine. When stopped at a light though, the car starts shaking. On one occasion at a light when trying to accellerate, the car would just sit there and buck; then i took my foot off of the gas, and car started accellerating on its own (without me touching the gas pedal); I actually got the car to go to 30mph without touching the gas. This particular incident happened only once and since then (OVER 3 months ago) it hasnt happened again. The only thing that remains is the rough idle when stopped at a light or in Park/neutral which is annoying the hell out of me. I finally took it to a shop in my neighborhood and they couldnt find the cause. Any suggestions you have would be greatly appreciated.

thanks!!

Tom

[JohnWayne]

check out the search button thingy i think that there was a thread about this a little while back.

good luck

[manic mechanic]

I somehow remember having a similar problem on an older Sunbird and the problem was the torque converter clutch switch (TCC).

I think I disconnected it and the problem went away. Eventually the TCC switch had to be replaced.

Here's an older Z24 sytle ... http://www.v6z24.com/howto/tcc

And from about.com .... http://autorepair.about.com/cs/doityourself/l/aa011703b.htm

[nebula72]

Thanks for the input. One question tho. I am having the rough idle in any gear including Neutral, Park and Reverse.
Did you have the rough idle in all gears as well?


Tom

[orangej]

It could be the park, reverse, drive, neutral box. On my 92 GT 3.3L when I had that similar problem it was that gear box (if your automatic shifter is in the middle of the two front seats that is where it is...the thing showing you what gear you are in). It was sending the engine the wrong status of which gear it was in and trying to over correct itself. (Thinking it was in "park" when it was really in "drive" that kind of thing.) Changing it was what fixed it. Maybe this will help, I hope.

[SilverGAGT04]

Is the fuel pressure regulator leaking?