Hi guys, ive got an Evo 7, been having some issues with idle since the motor has been built. It pretty much keeps changing the idle where sometimes it idles at 1.9k then 900rpm even though the idle screw is all the way out.
Now the car has been tuned and the tuner said its a mechanical issue hence he only tuned it to gate pressure. We have tried swapping parts with another Evo, such as the idle stepper motor etc nothing seems to fix this issue, any ideas guys? The tuner is saying throttle body because there are no boost leaks and it holds 17psi with no problems on gate.




Specs are as follows. 2.3 Liter forged stroker, GSC S3 Cams, Stock Cam gears,
FP Black Turbo, Speed Density Intake Kit, 255LPH Double pumper, Bosch 2000CC injectors.

Tuner says go to mechanic, Mechanic says go to engine builder....
just a long blame game going on.

 

I had an 01 vii idling funny for a few months. No one seemed to know what the problem was. Mechanic said it was no big deal. Till the morning I was hauling a$$ up Sanyo with snowboards in the back. Didn't hear any noise but the passenger pointed out the smoke from exhaust was thick. Pulled off at the rest stop and there was oil all over the back bumper, and under the hood. I think a valve was bent, the seal was blown, and some interference damage on a piston. No snowboarding trip for me. I had the mechanic put a whole new engine in that car. It was cheaper than repairing all the damage done. I never found out what caused the damage. Just to be on the safe side, I recommend being easy on the car till you figure it out. I hope for your sake it's just a dirty maf or something relatively easy to fix. Best of luck.

 

Is the TPS clocked properly?

 

It's not going to be a MAF related issue since the car is tuned without it (SD).

TPS would of been checked over by the tuner and adjusted correctly.

It's not going to be a damaged valve either since the engine was only just put back together and has not been thrashed yet.

What else could it be.....