i was driving the other day and came off the M5 and stopped at the lights where my engine began drop its revs well below idle and it began to sound like it was going to stall, after i realised what was going on it stopped and returned back to normal, the aircon was off. then yesterday it happened again i think it might be the idle speed controler but why would it only misbehave occasionally for no reason regarding driving style prior.
if it is the idle speed controller how do i adjust it?

it use to happen with my tf as well, either after higher speeds, or visited redline :D what i'll do is just back off the brake a little, then it'll go back up and as if nothing had happened afterwards

My KE does this aswell, its a pain because its only occasional so if I do anything to fix it Im not going to be able to tell whether or not it has actually fixed it :(

Interested to see what people have to say on the topic though, could give me some pointers aswell.

I hate to be one of those assholes who says this, but: Use the search function.

There is at least eleventy billion threads on this.

But for your convienience, here's the rundown:

Have you disocnnected you batttery lately? If so, you may not have given the ECU enough time to reset itself.

OR

It may be your ISC. A temporary fix is letting out the big screw on the throttle body. Thats what I did. My revs are still low, I'll need to have it looked at come next service. But at least its driveable!

:D

Thanks for the reply mate, Ive got a spare ISC so I guess Ill whack it in and see what happens :)

n make sure you let us know cos its pissin me off toooo!!!

base idle setting.

clean your throttle body as well.

mine does this too, disconnecting the battery hasnt helped either.

however, mine has an electronic throttle so i cant just turn the screw cos there aint none! will get it looked at next service...

another thing mine does that yours might do too, is if i rev it a bit in neutral or park and let the revs drop to idle, i'll drop down to about 300rpm and the rise back up to normal idle (which is too slow at around 5-600rpm). Before i changed the old air filter it would stall completely

disconnecting the battery causes this problem!

well b4 touchin the isc control make sure ur intake are not leaking and the maf sensor is workin properly ie plug ins and wires are intact. just a thought:think:

Make sure all the hoses are fitted properly and in working order. By hoses I mean between the airbox and TB, and the emission control stuff.

Also make sure you don't have a vacuum leak somewhere :) There is a thing called vacuum lock - now someone correct me on this as I've never experienced it - that has the same symptons as what you said but leads to stalling, and has something to do with turning full lock at low speeds and braking...? Now having a vacuum leak will have the same effect - that is, loss of vacuum!

hhhmmm ill take a look but i havnt touched anything under the hood for a while now it just decided to do it one day and mostly after long fast trips on the freeway but ill have a look anyway,
it reminds me of a loner car i had for a while it was an old holden camira but this one would actually stall when sitting at the lights lol.