ok well my friends 99 RS is idling at like 4500 rpm, its got about 75k miles on it, under the hood u can hear a very very loud hissing noise, which points me in the direction of a vaccume leak, the dealership said replace the intake mani and tb gasket, we did and it still doing it, its coming more from the right side of the intake manifold, but like when its idling high, u can hit hte gas lightily and itll drop to about 2k then kick back up again, i thought it might be the idle air controller, but i didnt htink it would make that loud hissing noise...any thoughts ?

check out the tps
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Chris
96 ESI 5 spd
Milwaukee, WI

Originally posted by Z87RSMan
the Mustang is an American icon...I have one because it sounds great

I say check all of the vac lines off the intake mani. Also, maybe light a cigarette and hold it near the mani in different locations while the car's idling high like that. If you have a leak somewhere, it may pull the smoke into the mani and you could see it. Otherwise, check the vac lines that run next to the timing belt in the back. I had one of those go and the idel started to go up and up. Good luck!

Originally posted by DR1665
Also, maybe light a cigarette and hold it near the mani in different locations while the car's idling high like that.

^ hopefuly it's not a gas leak if you do that. :P

Even for a bad vacuum leak 4500rpm is high, unless the leak is a monster one, and then it should be easy to track down. Check TPS, IAC. Check the throttle cable, he may have the tension set wrong and be holding the throttle plate open.



http://www.exileracing.com
una salus victus
Mods List: http://highlander.dsmpower.com/sig.htm

Happened to me. Intake manifold is not tightened enough.



Jon

1997 Eclipse RS

13.887@104.648 5/30/03

www.haiokuracing.com

KOOL! LOL, sorry. I bet he^^^ is right