I have a 2002 Z24, manual trans, and it has a bouncing idle (anywhere from 1100-2500 RPMs). Also, if i pump the breaks, the idle continues getting higher and higher (gotten it up to 3500rpms). Does anybody know what could be causing this, I have to get this car working as its my only means of transportation!!!! Thanks for your help.
anybody? i could really use the help
Don't know?
How many things affect your idle?
-you can set the idle manually (idle needs to be adjusted)
- IAC (bad or excessively dirt idle air control sensor)
- Throttle cable (throttle cable binding or stuck)
- Position of butterfly (sometimes they can get gummed up and stick)
- vacuum line (? There is at least one vacuum connected to the TB)
Could it be a bad vacuum line?
It's not the IAC, I replaced that. Checked all vaccuum lines and they seem fine, checked all the connections to the thottlebody and the tb itself and cleaned it all up. Can anyone explain why my car idles higher and higher when I'm hitting the brakes?! I think thats so weird.....
I would think a vacuum line probably the MAP sensorīs unpluged or a hole in it.
Sounds like a vac leak to me because when you hit the brakes you are using vacuum and there fore changing the vac reading slightly which with a leak will affect idle.
I've heard you can take a propane torch, open the valve but don't light it, and spray propane around under the hood by the engine with it running and when you get near the leak the idle will go up.
I had a vac leak once that was so bad it idled at like 3000 rpm and since it was on a MAF car it was letting in a ton of extra unmetered air, so it caused it to run so lean that the headers started to glow red hot in less than 2 minutes from a cold start. I found that the IAC had a tear in the diaphragm so that even thought the IAC thought it was only letting in the proper amount of air, it was actually letting too much in, the computer and tps were thinking the car was at idle so it didn't increase the fuel to match the air.
That wasn't on a J-Body though and since these cars have speed density it may or may not affect your fuel mixture but you'll want to get the leak repaired soon. I'd check the vac lines running from the throttle body and intake manifold.
Scott
2002 Audi S4, black
1996 Z24 auto, red
Yeah I thought before that I heard a hissing sound but haven't heard it recently. Anyways...I'd probably be better off having a shop find the leak and replace it. Does anyone know how much they might charge to do so? Doesn't seem like it would be too pricey but I'm on a super tight budget right now
, thanks for you help everyone
