Hi, what rpm are you guys idling at when engine cold and warm?

I took off my intake plenum to paint and now that i put it back on i'm idling at around 900-1100 seems higher than i remember, do you think i have a vacuum leak?

Okay so i got the service engine light, it is code 35. Could be a vacuum leak or bad iac valve. Basically my car idles at 1500 until warm then drops to 1100, once warm and restarted idles at 1500 for about one minute tops then back down to 1100.

I read online to test for leaks with a propane tank, i put it up to all the vacuum lines i could find and no stumble or change in idle. i thought it might be throttle body gasket or intake gaskets cause the idle problem started after i re installed my plenum after painting it, but nothing. I put on new gaskets so they should be fine.

The internet said maybe egr but my egr is dissabled on my reprogrammed ecm.

Could any of this be caused by a dead battery cause i hadn't started my car in a while and had to jump it. I tried resetting my iac from the method i found on pennocks. it helps in the sense that it idles at 1100 instead of starting at 1500 then slowing to 1100 after one minute but its not the 900 my car was idling at before this.

I also read that i need to drive above 35mph for a minute to re adjust the idle but my car currently doesnt have insurance, anybody know if there is any truth to this and if it would apply to my situation.

I was thinking of getting a new iac and see if that fixes it, if not then it would rule it out then i know i have a vacuum leak.

Any help is greatly appreciated, thanks guys

You don't say what engine you have, but if it's the 2.8, I'd say your EGR tube is cracked.

brad12329 wrote: i assumed it wouldn't be the egr cause it was disabled at the ecm.

That makes no difference. The flexible metal tube is still connected to the underside of the intake manifold. If the tube is cracked (or not attached properly at either end), air will be sucked into the intake system.

If your ECM indeed has the EGR deleted/disabled, eliminate the potential problem of a cracked metal EGR tube by installing a small plate over the opening on the underside of the intake manifold.

Okay mission acomplished, those little bolts were hard to get to but i slid a piece of a pop can in there and it worked!!!

Thanks guys, she runs beautiful again :)

And sounds very nice since removing my cat and putting a straight pipe in.

brad12329 wrote: ...and it worked!!!

Don't sound so surprised!