I'm trying to diagnose my engine's problem. I'm a 97 GS atx, in the past week my car's CEL has been off and on. What's been happening is after I've been driving and stop at a light the car begins to rev, the only reason it doesn't move is because I'm on the brake, but it gives it quite a bit of throttle-enough to jolt forward until I stand on the brakes. Then it just stops. This has happened 3 times, but I've driven quite a bit, it's very sporadic. I'm thinking the ECU thinks my idle is too low and thinks the car is close to stalling so it gives throttle. My car has idled at 400 or so for about a year, I know that's low but it's a smooth idle and I've never had a problem before. Could it be something else, timing or something? I don't want to have to take it satan and fork over $60 for them to "Look" at it. Thanks.

mos def paranormal activity here......

I know, I could understand if it was something that happened all the time when at a certain RPM level or other circumstances, but I have tried to recreate it by sitting idleing after driving with no luck. It just goes nuts once every few days.

check all the vacuum lines. if they look good, check the TB gasket and the IAC.

holywater.... :)

All of the lines looked good and the TB gasket checked out too. I was rooting around in there for a couple hours and couldn't find anything wrong. I hope this doesn't turn out to be a dumb question, but what's the IAC?

Does anyone know whether or not it could be something in the ECU being triggered by a low idle? I just can't find anything physically wrong that would explain it.

Hmmm idle surges are normally caused by a malfunction in the iac go to autozone get that cel checked...iac malfunction will cause a cel it will cause a CEL...i get a mini surge cause my IAc is closed a lil too much (you can adjust it.....look at your chiltons :) manual will help a lot) btw the chiltons teaches you how to diagnose if its the iac itself that is malfunctioning

:thumbsup

IAC=idle air controller. its located in the throttle body and regulates the butterfly valve to let more/less air in to stabilize idle. after years of gunk that passes the filter, its common for these to get sticky, leading to sporadic idle. clean it off and re-install (be carefull, the TB gasket is very brittle), if you want to know how to do this just search. i used some mopar combustion chamber cleaner to do mine, and my eclipse was purring afterward. any leftover cleaner can be purged into the PCV hose while the throttle cable is held at around 2000 RPM. its great for shooting sludge out of the engine. ;)

thanks guys. Hopefully that works. If not I'm sure I'll be on here again tomorrow with more questions.