Ok guys,
I have an Evo IV that is basically a DD on pump gas (here in the Bahamas, thats 87-89).
Problem started recently after a full tank of gas. Around 2.5K feels like a fuel cut is occuring with a sharp deceleration (feels like hitting a wall). Occurs most times during deceleration as well from above 3K
Idle is not a problem as far as i can see.

Ive been running the same tune for about a year now with no complaints, have never gotten the fuel trims to read as they should and that pretty much stopped the tuning process from completing.

Ive swapped out the TPS, Cam sensor, MAF and checked for crankwalk and still the problem persists.

Im using Evoscan and an AEM wideband to log.
I attached a log at idle and a log at free rev in neutral (it cyclically revs to about 2.5-3K then back near 900)

Any help or ideas would be appreciated.

My mods are
Evo 9 turbo
Evo 8 injectors
forged bottom end
turbosmart BOV
turbosmart MBC (lowest boost setting always)
Apexi power intake
Apexi N1 exhaust

 

Based on the datalog, I'm inclined to believe it was either a damaged ECU or firmware problem. You seem to be getting fuel cut for no apparent reason.

Can you remove the ECU, open it up, and take a photo of the circuit board?

 

I thought about the ECU being the issue. I swapped out the EVO5 ECU im using now for the evo4 ECU the car was born with. Same result. Im going to swap it out again for a PowerFC ECU tomorrow or so that has a EVO 5 basemap and see if that can help. that will definitely rule out the ECU as the cause i believe.

 

same prob here, think it may be in boost controler/

 

Out of curiosity, how's the ECU swap? Any results? If it's not the ECU, then have you checked if you have a bad ground somewhere?