420A Rough idle

[609DSM]

I'm having really rough idle in my 1998 eclipse gs. I suspect it's the IAC, saw a video of someone having a similar problem and when he turned on the a/c and got the blower running the idle dropped a good 500 or more. My car is having the same issue with the same symptoms, but not 100% because I havent checked everything out. Has anyone experienced this issue or know about it?

Car should idle around 1000 if I'm not mistaken, it does that on a cold start then when it heats up it gets really rough. Idle surges 750-800 down to at least 400.

 

[BLACK'98DSM]

After it's warm 1000 would be too high. I'd say 800 is fair.

 

[609DSM]

After it's warm 1000 would be too high. I'd say 800 is fair.

It still has idle surge when at operating temp and that's what bothers me, sometimes it gets really rough like she wants to stall out and if I turn on my air and the blower motor is running it dips down even further.

 

[BLACK'98DSM]

It still has idle surge when at operating temp and that's what bothers me, sometimes it gets really rough like she wants to stall out and if I turn on my air and the blower motor is running it dips down even further.

Sounds like a major vacuum leak. Check all your hoses and ports

 

[609DSM]

Sounds like a major vacuum leak. Check all your hoses and ports

Vacuum leak is what system do you think? I do have a p0455 but that's an EVAP system leak, not sure if that would effect idle. I do have surging during WOT I'll lose power for a second but it doesnt happen very often. Still trying to diagnose the issue and pinpoint symptoms though.

 

[BLACK'98DSM]

I do have a p0455 but that's an EVAP system leak, not sure if that would effect idle.

Yes it would. It is still part of the vacuum system.

during WOT I'll lose power for a second but it doesnt happen very often

And that sounds like a misfire.

 

[609DSM]

Yes it would. It is still part of the vacuum system.

And that sounds like a misfire.

Hmmm. Definitely need to figure this out. Thanks for the input! I think I know what to check when I get home.