Rough idle when cold

Col · 07-25-2004, 05:50 PM

Hi

I have a 1984 N/A 944.

Lately when cold the car starts fine but idles roughly and I need to keep my foot on the accelerator to keep it running smoothly.
The idle speed is about 6,000 rpm at this stage.

When warm it idles fine at about 8,000 rpm.

Any advice on the possible problem.

Cheers
Col

Gordon Rankin · 07-25-2004, 06:11 PM

This is joke right?

Makenzie71 · 07-25-2004, 06:24 PM

I believe he's adding one too many "0" to his idle numbers...a little common sense could tell you that...but a smart-ass un-helpful post was far more apropriate, I'm sure.

General tune-up. Check your plugs and wires. Then check your filters. If none of those help the situation start searching for a vacuum leak.

will944 · will944's Garage

Yeah....I would definitely check your vacuum lines....typically break around the Idle Stabilizer under the Intake.

Col · 07-25-2004, 07:17 PM

Sorry. I did put an extra "0" in the idle speed.

Thanks for the responses I will check plugs ,wires, filter and vacum as you all suggest.

Cheers
Col

Makenzie71 · 07-25-2004, 09:03 PM

^I have to look into that myself....

krahm · 07-25-2004, 11:07 PM

All good suggestions. It could also be a combination of problems, though, so if you do all the above-mentioned things and you still haven't got it running quite right, think about pulling the injectors and having them cleaned and tested. Also, check to make sure the 02 sensor is working properly.

CJFusco · CJFusco's Garage

my idle would sometimes be a little rough. i readjusted the idle to sit between 900 and 1000, knowing damn well that i need new plug wires. It helped a lot, and the new wires are on their way.

TheStig · 07-26-2004, 08:16 AM

usually a really bad idle like that can also contribute to a ripped intake boot. Check that area. If not check the vacuum lines under the throttlebody and boot and to the auxiliary air regulator. I had a loose one on this newer car and I had the worst idle.

Andy

Lawrence Coppari · 07-26-2004, 10:23 AM

"usually a really bad idle like that can also contribute to a ripped intake boot."

How does a bad idle rip the boot?

Cebu · 07-26-2004, 10:55 AM

I agree withe the assesment of tears/cracks in the intake boot..my personal experience.

Col · 07-26-2004, 04:21 PM

Thanks all for your advice. I will give all the items mentioned a good check on the weekend and replace as necessary. Will also adjust the idle speed and if no improvement replace the aux air valve.

Cheers
Col