Whats up Jay?
Anyway my 98 did that. Even though it was an M-6 at idle in neutral it would do something very similar. My problem was the exact same one as Fran D. The #8 spark plug wire had ended up boning me.

 

Hey Jay my 2001 z did this once and its brand new I actually thought that my cruise control somehow messed up or that my foot was on the gas funny cause it was so weird. Anyways after the one time it has never done it again.

[ December 27, 2001: Message edited by: Weltall ]</p>

 

I had a similar problem last summer. It was dog hot outside and raining. It seems the combination of the windshield wipers, A/C, headlights and hi-amp stereo just about killed the charging system...

 

Thanks again guys for all the info! I feel better now knowing that this has happened to others here before and it seemed to clear up just as mine did.
JAY

 

Mine did something similar once but instead of high idle or surging it idled low. I started it leaving work one day and I noticed instead of the normal sound (a vrooom followed by a cold idle) it just went directly into an idle. I looked at the tach and it was only about 400-500rpm. It slowly started to get even lower and I had to tap the pedal to keep it running. After a while of this I put it in gear (drive) and it shut off. I turned the key off, waited a few seconds, and started it again to what was a normal startup (vroom, 800rpm, slowly coming down to about 600rpm once it got warmed up). It has only done this once and that was obout the 40,000mi point. I now have 55,000mi and it has never done it again. Oh well, I only worried about it for a day or two. This is the first time I've heard other people say anything about their's so I just kept it to myself. I know electronics are tempermental sometimes, especially to temperature differences.

 

Hey guys. i seem to be having simialr porblems. I Just did a plug and wire swap but this has been happening befrore that. My volt gauge charges low on aregular basis, usually areound 10 (right befrore the yellow). I'll start the car and the idle will drop then raise then drop and then the car will shudder really bad. I will bw replacing the battery soon and hopefully that will help, if not i will replace the laternator and work on from there.