[BGR]

I had started a post about my M Coupe hesitating under full throttle any any RPM. Unsure if this catastrophic issue is related to that.

Known variables:
-Car arrived with a newly installed used engine 60k mi, valves in spec) that only had a few miles in the new chassis
-Car arrived with ESS supercharger tune (no supercharger), so couldn't be driven hard with the newly installed used engine
-Successfully flashed to ESS S54 tune
-Car experienced .5 second hesitation under full throttle for a couple hundred miles
-Car smelled a little rich but otherwise ran ok
-Only check engine codes were for oil temp/level sensor and EGT probe, along with both banks of O2 sensors
-Attempted to flash car back to OEM tune, but using the "recover" feature caused encrypto error
-Able to flash back to OEM parameters using "program" function


After flashing back, car would not increase over 1,400ish rpm. You can get up to 1,600 by stabbing the throttle, but it just drops down to 600. It is almost like fuel is being cut. It also smells incredibly rich. If you hold the gas pedal at any throttle position the revs will climb until they hit than wall them drop down, and the cycle will continue until you let off the gas. Letting this cycle occur for 30 seconds yields a throttle actuator error, but all throttle actuator tests appear to be fine.

The guys at ESS are 100% certain that the tune would not cause any issues like this and are sure it is hardware related.

My performance BMW shop has spent 12 hours testing and trying to diagnose various items but have not had success pinpointing the issue. They are going to be pulling apart the intake and plenum to get to the actual throttle bodies to see if somehow the shop that out the engine in maybe left a part loose that worked its way out and is jamming or plugging something. I just find it hard to believe that this would start right after an update to the DME. If they can't find anything with the actuator, I will have to replace the DME.

The gentleman I bought it from (Tommy) has remained in communication and has promised to help pay for whatever the final costs of getting the car running properly are.

I am more starting this thread as a diagnostic diary in case anyone else ever had an issue like this. But if anyone has any thoughts or suggestions feel free to post up.