high idle when cold

[White93z34]

this is about my brothers 93 z34. 88 on the clock. anyhow he tells me when its cold out and he starts up the car it will go to 3000rmp and sometimes hit off the revlimiter untill the car warms up it does that but after that it idles fine. he also claims the brakes suck when it is doing that? not sure what to think about it. but dosen't sound healthy at all. i smelled the oil dosen't reek of antifreeze but didn't get to see the color cause it was at night.

[Robby1870]

Hmm....tell him to check the brake booster vacuum line. A bad one would cause a very high idle like that (vacuum leak) and if the brakes done have vacuum they wont work very well

[White93z34]

if it were a vaccum leak i would suspect that the brakes would suck all the time. but his do just till the car heats up.

[913_4se]

i had the same thing happen to me it was the IAC then it did it after that and it was the intake leaking when it is cold start it up and spray some intake cleaner or WD40 around the intake see if the motor changes RPMs if so your intake is prob leaking