So probably once or twice a month when I start the car it'll idle funny. The idle will bounce from 500/600rpm - 1500 rpm when starting from a cold start. After it has warmed up a little it starts to sound/feel like it's only going off of 3 cylinders. Weird thing is once I go WOT the problem goes away(After it reaches normal temp). Idle goes back to normal and feels like its firing off on all 4's. If I don't go WOT the car still feels/sounds like its running off of 3 cylinders and problem won't go away until I go WOT.

I've cleaned the airflow sensor, replaced intake filter and got new spark plugs that are gapped 0.23-.025(can't remember exactly).

Anyone have any ideas what could cause this issue? I've searched but couldn't really find the same symptoms. Only happens a couple times a month randomly.

 

does it happen after it rains? getting moisture in the coil pack some how?

 

It did rain last night and the car still had a bunch of water still on the exterior. I'll have to keep that observation in mind.

 

I just thought of a genius idea. If there is moisture getting under the spark plug cover I can just add uncooked rice under there. The rice will suck up the moisture and when I am driving around it will cook thus me = carbing up.

 

It also happens when its dry outside. Was leaving work and it was pretty hot out and I ran into the issue again.. After it was warmed up I WOT it and the problem went away. Issue happened again this morning and after 1-2 minutes of driving it was warmed up, I hit full boost and problem went away. Seems like something is clogged like injectors or something and pushes the clog out when I WOT? Anyone have any other suggestions?

 

how long do you wait for it to warm up? is the temp over 180 and in open loop? it sounds to me like its a closed loop issue. has the ecu been re-flashed?

 

Only temperature gauge I have is the one on speedo cluster. The car has been tuned professionally and that was a good 4-5 years ago. Issue started occurring the last year and more so recently.

 

Your ISC (idle stepper controller) is probably sticking. Very common problem for the 4g63. The OEM replacement is pretty expensive, few hundred bucks if memory serves me. I believe you can get one off amazon for 50-60 bucks and i have read mostly good things about them. Its easy to get to if you wanna pull it off to inspect it.

 

Slightly off topic but on my old leon cupra R I had an oil temp gauge, and that told me it takes another few minutes for the oil to get nicely up to temp after the coolant, so if you're waiting for the coolant to get up to temp and then boosting it like a madman, the oil probably isn't quite there yet. I'm not saying it's causing any damage or anything like that but you mentioned several times you wait for it to get up to temp so I thought it was worth mentioning