2000 Blazer Super High Idle

[zedbear]

A friend has a 2000 Blazer with about 100K miles. When it's started cold, it idles at 2000 rpm and then slowly increases to about 3000 rpm after a minute or so. It is running on all cylinders and seems smooth otherwise. We removed the TB and IAC and cleaned them up but it didn't help at all (didn't think it would but the TB needed cleaning anyways). I know the IAC could just be defective but he's now trying to avoid throwing parts at it. Somewhat recent parts replacements include the cap and rotor, ign module, and the MAF sensor. It had been running rough and stalling before. Then it sat for about a year and now this crazy idle problem. Any ideas? Thanks!

[pj5454302]

A friend has a 2000 Blazer with about 100K miles. When it's started cold, it idles at 2000 rpm and then slowly increases to about 3000 rpm after a minute or so. It is running on all cylinders and seems smooth otherwise. We removed the TB and IAC and cleaned them up but it didn't help at all (didn't think it would but the TB needed cleaning anyways). I know the IAC could just be defective but he's now trying to avoid throwing parts at it. Somewhat recent parts replacements include the cap and rotor, ign module, and the MAF sensor. It had been running rough and stalling before. Then it sat for about a year and now this crazy idle problem. Any ideas? Thanks!

 

Is the ses light on?

[zedbear]

Not at the moment but he said it will come on if he runs it long enough. I think it was a cat converter efficiency related code which as far as I know won't effect anything really.

[hockeypro1411]

I'd put money on the IAC or a pretty serious vacuum leak.