ZE85

Hello Readers,

I have a heavily modded 1990 TT with a Z1 Stage II long block, Nismo 740cc injectors,Sport 600 turbos, dual pop filters with Selin MAF translator, 2.5" down pipes through to test pipes, running on E85 with a Gizmo booster controller. I have recently begun having a stalling issue. I have done a ton of reading on the subject, and have followed several suggestions from people who have suffered through this issue in an attempt to remedy my situation. But still the problem persists. When my car is first started, the rpm will hover between 1300 and 1500. When they settle to a normal idle, the car purrs at about 1000 rpm. If I give it medium to heavy throttle (even in neutral), then releasing the throttle, the RPM drop to about 300, the car sputters, then the rpm bounce back to a steady 1000. But now that the weather is getting hotter, if I run the a/c, the car idles steady but at a little lower rpm, around 8000-9000. When giving her throttle at this time, she drops to about 200 rpm then about 75% of the time she will stall completely. She starts right back up every time, and purrs at a steady idle until the throttle is applied again. About the only time the rpm don't dip before returning to normal idle from open throttle is if I coast in gear slowing to a stop and then depress the clutch when the rpm are around 1000. There are no other drivability issues. She has full power, runs strong with no stumbling or misfires. I have checked for vacuum and boost leaks. I have replaced and set the TPS, I have removed, ohm tested, and cleaned the IACV/AAC. I have also cleaned the throttle bodies and MAF sensors as well. What am I missing? Can someone please help?!?

Thanks,
ZE85