My eclipse Recently started acting up, it had some down time for about a month or so.
Heres whats goin on, i can start my car and drive it for awhile with no problems. but when i stop somwhere, or turn it off for a little while(10 mins or so), and then i start it, the idle will start to surge between 2000rpms and dying, it does clear up after 2mins, with me givin it gas. I cant figure out why its doing that, ive checked the TPS, and IAC.

My car is a 420aTurbo with SFMU and FCD

My cars acts like that if I need to burp the coolant. From a cold start works fine, shut if off and wont idle right for a minute or two then its fine til I shut it off and start it again. Might be the same thing happening to you.

Originally posted by Islandertalon
My cars acts like that if I need to burp the coolant. From a cold start works fine, shut if off and wont idle right for a minute or two then its fine til I shut it off and start it again. Might be the same thing happening to you.

Burping the coolant shouuld have absolutely nothing to do with anything of the sort. If you have to keep burping your coolant, you have other issues then as well. You are getting air into the system some how.

But to the OP, almost sounds like an IAC or a vacuum leak, but a vacuum leak would be all the time upon start up, unless you have a hose that is leaking when its getting warmer temps, but I cant say I have seen that a lot before.

What are your fuel pressures at when this happens?

I had a cracked coolant line when i was away from home, but was only slowly leaking so i just left it until i got home. It would act like I decribed when enough had leaked out. Figured if it worked for me it might work for the OP.

did you put a multimeter on the IAC and check the IAC? If not, set the multimeter to ohms and touch the leads to pins 1 and 4 on the IAC and then 2 and 3. Haynes manual says it should be between 38 and 52 ohms. But mine is 52.5 or so and so are all other 420a IAC's that i have checked. If it is way out of specs, replace. Can run kinda expensive at autozone. Try rockauto.com for it or any other parts you need they are cheap and have alot of parts for everything. Got my IAC for like 35 shipped or something like that compared to autozones $80 plus last i checked.

Thanks for the help guys, im gonna test the iac with the mulitmeter and check a few things. Ill let yall know how it goes.

Ive checked the iac and it reads 52.8 - 53.5 on the multimeter. my idle fuel pressure is 20psi.
When my idle flucuates, my vacumm does too. but once i get the car movin it clears out. this only happens after my car is at operating temp, and has been sitting for 10 mins. Any help appreciated guys.

May also want to check the CTS as well...

How can i check the CTS?

Also i notice when i free rev my car it bogs a little bit. When i disconnect the vacumm line from my sfmu my car revs fine, no bog.
Could all this be a fuel problem?

Sounds like a vac problem.. had this happen to me on another car (01 Jetta) and it turned out to be some tucked away vac hoses that are easy to miss if you're just scanning the engine bay.

It's up to you if you wanna do this, but I took some carb cleaner and sprayed down my vac connections and lines with the car running, and when the engine revved (from the intake of combustable fluid) I knew I found my leak.