Thread: Strange rpm wobble and CEL flashing

I'm driving a 99 Grand Prix GTP with the 3800 series supercharged engine, the other day I was driving down the highway, not incredibly fast, maybe 150km and my check engine light came on and started flashing. I stopped and started looking for problems under the hood and checked the gas cap. Everything seemed to be fine so I continued driving. Nothing seemed to be incredibly out of whack so i have since let it be. The only thing I have noticed different is that if I punch it, it will rev to about 3100rpm then sit there and keep accelerating, then it kind of drops a bit and takes off to 4000rpm where it sits again the same as at 3000. Today I noticed when it was at the 3000 range the car jerked slightly but nothing that seemed to be a real threat. As I was looking for solutions i found a few suggestions saying it could be an air leak, but it idles fine so I am not sure thats the problem. I have also read it could be spark plugs or coils but I would like to know for sure before spending money on that. I should mention that during the summer it had a problem with sparkplug gap and I had to have it towed as it would not even idle, could this be the problem again?

Thanks
Austin

I forgot to mention that the SES light is on constantly until it gets into that 3-4000 rev range for a few seconds then it starts blinking. Is this normal?

Is it ok to drive it like this as long as the light is not flashing? Everything feels fine until its almost wide open

thanks for the help guys, its going in on tuesday, will report with the problem!

just fot the car back and turns out it was a misfire on cylinder 3. Plugs were replaced this summer after a gap issue but wires were not and that seemed to be what was causing it. Plug and wires were replaced and everything seems to be good. Thanks for all your help, I am loving it here on the forum!

Austin