My 92 RS will not idle right.When i start it it rev's up and down untill it dies.Cant find any vacuum leaks.Replaced MAP sensor,Idle air control valve,o2 sensor,throttle position sensor,and rebuilt the trottle body.If i cover the throttle body with my hand so it dont get much air it plains out and runs good until I turn it off.PLEASE HELP

 

Sounds like the EGR might be sticking open. Any codes?

 

Sounds like you have the exact *opposite* problem to me! I'm running rich and don't know why (see my post if anyone can help!), and I'd say you're lean - that would explain why the car runs when you cut off its air flow. You need more gas in that engine ... I'm just gonna fire off some ideas: Perhaps fuel pressure regulator, fuel filter ... ?

 

all the things i listed just about it spit code. i replaced everything the codes said to. o2, map, iac.

 

that is really odd that your car will run well with the throttle body covered. it should be choking out.

if the engine can run while you are plugging the intake side, i would think that you would have to have a bad vacuum leak somewhere. an engine NEEDS to be getting air for it to run, so it is getting it from somewhere (vacuum leak).

*not to be rude, but a "please help" thread tittle wont get you as many replies because some people are sick of them, and it problem is not described in the title. i would suggest changing to the title to something along the lines of... "car wont idle unless you cover the throttle body"

 

might wanna try some seafoam. i had a problem mostly like that and after replacing the egr valve and running some seafoam through it it was fine.