Help me diagnos my idle problem please

[caseywan]

Alright, for the past week or so my car has been having trouble idling. I had just put a Crane Firball ignition on it a few weeks before and it really smoothed out the idle and it sat right at 900rpm. But now when I stop it will idle at 1500rpm for about 5 seconds and then starts bouncing up and down between 500-1500rpm and sometime will die.

I assume it's some sort of vaccum problem, but I don't know where to start. I also get a very slight stumble when revving off idle. Any help would be much appreciated.

edit: something else I just thought of too, is I just noticed my heat doesn't work either, I don't know if there is a vaccum controlled valve that may be tied into this somewhere or what.

 

[Busted07]

You might wanna get this moved to tech... if you post questions like this in talk, youll suddenly have out your voltmeter and will be checking voltage at both ends of your noodle.

 

[Strype]

A) Should idle between 600 and 1000 depending on cam

B) Carb Cleaner. If you hear a whistling noise, that's a vacuum leak. Spray carb cleaner around intake and TB until you don't hear it anymore.

C) Buy a new TPS sensor ($25) and set it to .99

D) IAB probably could use changing, or at minimum a thorough cleaning. ($70)


JRichter has a great surging idle checklist if you do a search on it

 

[jrichker]

See "Help me create the Surging Idle Checklist" at http://forums.stangnet.com/showthread.php?t=534062
for help with your idle problems. The first post contains all the updates to the fixes. I continue to update it as more people post fixes or ask questions.

 

[caseywan]

I just fixed the RPM numbers cause I had them all 1k too high, I don't know what I was thinking when I typed that, it was a rough morning.

Thanks for your help though, I will definatly use that checklist.