Ok so I’ve been trying to chase down an idle issue in my evo 8. I got that car idling great warm. I’ve replaced the tps and iacv. Cleaned maf, throttle body. No vacuum, boost leaks or cel. Problem is cold start and idle. When I cold start the car idles high for a few seconds then kicks down to like 900 then struggles there and eventually kicks up to high idle again. Also seemed like it was running a bit rough for a second when I started it this morning. I’m lost. Any help would be nice. Btw my ac runs even when it’s turned off. Not sure if it’s supposed to work like that. My dodge does.

 

no the a/c shouldn't run all the time i would start there.

 

Ok. I didn’t think it was supposed to. But couldn’t find much on it. Al check into that. Probably a bad switch. I suppose i
could unplug it and see how the start tomorrow morning goes.

 

Yah i would definitely try that. Not only does the compressor put load on the engine, but the alternator also has to run the radiator/heat exchanger fans which creates even more load.

 

I unplugged it so we will see hot that goes. Isn’t there only one ac switch?

 

Stock Tune?

What mods?

 

Honestly not sure on the tune. Has to have one. It’s stock except for header with dump and exhaust. Built block/no balancer shaft.

 

Did you just purchase this evo?

 

^^^ This

My money is on the tune currently.

Has it always done this? Or all of a sudden?

 

A/C should turn off. Another option I've heard before is simple, but it could just be some ****ty gasoline

 

It just started this when it got cold. And I’ve had the car for a while.

 

My first thought was coolant sensor but u have no cel on. Someone told me to check the fan module but I think I figured that out because the ac is staying on. So I don’t think there is a problem with the fan.

 

pretty sure you may have tried this, but did you try to reset the ECU by unplugging the battery? i've had idle issues when i changed out my UICP in the past.

 

Also, for my evo, the A/C is ON even if the indicator shows its off when the HVAC setting is set to defrost the front windows. You may want to switch it to blow the face to test.

 

yes I have had the battery out multiple times. My dodge truck is the same way when running defrost. I know that’s supposed to be that way. But wasn’t sure about the car.