NoReason

Hello,

Can someone please ELI5 what is going on?

I wanted to swap out my APS 50/50 bov to a fully recirculated valve. I installed a Greddy FV with recirculation adapters. I installed the valve and no matter what setting from softest to hardest, my evo would not idle properly. My AFR at 1k idle would be from 11-12 and would spudder/pop as it would rev up and the engine would stall coming out of deceleration. Also the STFT would be at -25. While I am cruising, everything is fine. I threw back my APS bov and everything runs magical like it should. I am running a MAF and Tephra v7 if that matters.


So what is happening and did I just spend $200 to make my evo run like poop?

FTONOOB

What's the IAC doing during all this?

NoReason

Bouncing from 0 to 3 steps.

FTONOOB

That's with the Greddy?What's your ltft?

NoReason

Yes. LTFT is -5

FTONOOB

You have -30 total trim at idle with the Greddy, stalling at high revs and it all magically resolves with the APS. Get data pids for both setups at idle and WOT 1st gear pull to red line. Have you tried running that car with the MAF disconnected?

FTONOOB

Is it possible that the recirculation is stuck open?

NoReason

If anyone searches this and runs into a similar problem, the answer which fixed this issue is that I had to retune the injectors (scaling and latency) and rescale the maf because it was running so rich. I think what happened is that the old valve was leaking or not working properly and when I put on the new valve on it sealed the leak. It was tuned with the leak and ran great. Re adjusted everything and now it idles right and trims are proper.

Also, I readjusted the BISS as well for good measure since I never had done that.