Had the chance to try the "PID reset" procedure today. Held manual button, slowly accelerated to 100% for 40 seconds and released. Next acceleration seemed much better. Nice and slow from idle to 50% then on up nice. Bad news is, next accel was bad and all the rest were same as ever.

I have "very slow" idle to 50% ramp time selected but it's almost as if the ECU is ignoring this setting. Upon accel you can hear it ramping too fast, loading up (popping), ramping back down then repeating over and over. I haven't tried slowing down my throttle channel servo speed yet although I'm quite sure I could slow it down enough to prevent the popping cycle. I just wanted to try to fix it right first.

Could there be a failure to communicate with the ECU via the GCU? I now really think it's ramping too fast and won't accept the command to slow down. Just FYI: Problem is from 32K to 50K. After 50K it accelerates fine. Hangs (popping) right around 40 to 50K, EGT doesn't climb, pump pressure stays pretty low, RPM hangs.

EDIT: Just came in from a test run. Tried slowing the throttle channel down but no luck. Believe it or not, even slowing throttle-up response to 30 seconds(!) had no effect. I took over "manual ramping" with the throttle stick and could actually get a very decent throttle response - but it takes very careful stick jockying at the critical rpm around 40 to 50K. My ECU is NOT accomplishing the needed ramping in that critical rpm range. Interesting because other than this little (albeit serious) quirk it's a great running engine.

Anybody have a suggestion? Pleeeeeeeeeese. . . . .