I ran into my first small issue with the evo today. Last night I pulled off the throttle body because it was sticking and I wanted to replace the seals. That bad boy had a LOT of carbon build up so it's no wonder it was sticking. Pulled it apart, replaced seals, assembled it back together, and reinstalled everything.

Now today I notice that my idle sits around 1200 RPM where it used to be at 800. Every once it a while it will dip down to 1k but then it seems as though the motor is "catching itself" and bringing the idle back. My guess it's one of 2 things:

1. The carbon build up allowed slightly less airflow through the TB and the ECU has been compensating for this. It is now trying to relearn the idle.

2. The TPS is somehow off causing the ECU to ramp up the idle.

When the TPS was removed hash marks were used so I know it's exactly where is was before. Can anyone weigh in on if I should I try adjusting the TPS or wait a while? I put 20 miles on it today.

Thanks

 

Unfortunately its neither of those. The TB comes with a special sealant that goes all away around the perimeter to help seal the throttle body butterfly valve. I imagine you removed that sealant so now air is sneaking by thus causing your higher idle.

Search around on here and you will see what I'm talking about.

 

I had the same issue when I replaced my seals.. I picked up some dry moly lube and hit up the back of the TB. I got mine from the local grainger for 13 bucks. Solved my issue. Idle is a lot smooth as well.

 

Damn I had a hunch that there may be sealant there when I pulled the TB off but was crossing my fingers that there wasn't. I'll throw some on today and see if it fixes the problem