cold idles between 500 and 2000 rpm. Why?

SLO-BOB · 01-03-2007, 07:04 PM

A friend has an 82 SC. When she starts it, it seems okay other than it's very rich (smells bad)-way worse than my 77. After about a minute, the idle fluctuates rhythmically between 500 and 2000 RPM. That lasts about 20 minutes. Then it levels out. Any ideas?

Thanks.

HarryD · 01-03-2007, 07:55 PM

Could be lots of things. Check this chart: http://www.pelicanparts.com/911/technical_specs/911_cis_troubleshoot.htm

My car does the same thing when the mixture is off or it is very cold outside.

SLO-BOB · 01-04-2007, 04:24 AM

Thanks Harry. I was hoping it would be one of those- "Oh, that's a so and so......"

But this is a help.

HarryD · 01-04-2007, 06:11 PM

Bob,

CIS can be a real pain if you do not carefully diagnose the problem. While I appaud those who are willing to go it by themselves, sometimes, if you have a bonafide expert nearby, it may be worthwhile to pay the bucks to get it done.

My car was very surgey and I tried all kinds of things. I finally brought it to my mechanic who put it on the sniffer, noticed the mixture was way off, made a few adjustments and it has been running quite well ever since.

SLO-BOB · 01-04-2007, 07:08 PM

My plan all along was to recommend it goes to a mechanic. I was just hoping we would know ahead of time what she is in for. I'm making appointments for her car and also my car tomorrow.

Thanks again.