Bouncing idle (again)!

[todras]

Okay here's the scoop. Car had a falling idle last Spring. Sometimes it would even stall while the car was in motion! The clutch was depressed of course. Replaced IAC and problem solved. Also replaced TPS for kicks. Well the car is at it again but not on as big a scale. The car will run fine while cold but after a few minutes while sitting at a light the RPM's will drop to 500 and then jump to 1200. Sometimes volleying until the car stalls. Sometimes it's worse than others. Car runs awesome otherwise. Is their anything else I can replace. Vac hose? I just don't have the money to do the CPS if that's the problem. Car has 131k on it.

 

[Mike Kopstain]

Told you so? *runs for the door!*



Try cleaning the throttle plate. My 93' used to do the exact same thing, only when warm. It was carbon buildup on the throttle plate.

 

[todras]

I figured you'd see this. Ok that's a cheap fix I like to hear.

<small>[ December 10, 2003, 04:20 PM: Message edited by: todras ]</small>

 

[Mr Anonymous]

Read the codes.

 

[Speedy_91_SHO]

I believe the VSS can cause a weird idle.

 

[todras]

Last night I cleaned her out. Their was a little carbon build up around the bottom of the facing edge. The IM side was clean. Their was also some on the bottom of the TB where the TB plate met. Cleaned as best I could and the car seems to be running fine once again. Why would this little bit of carbon do this? The backside of my TB in my Contour was caked and never had this problem. I've on;y driven the car short distances but the idle hasn't dipped yet. Thanks Mikey!

 

[Mike Kopstain]

lol I was just giving you a hard time. I know how frustrating it is.

On my car, it happened after I did the 60k. I thought it was the EGR valve, so I replaced it, the DPFE sensor, and the IAB valve. It ended up being the carbon on the throttle plate. 5 minute fix.

Glad you got it fixed.