Hi Bob,

I would look at you trim switch, to make sure it is not having some vibration problem. Also, I am not so sure how hard it is to do, but you can modify the trim circuit to get more of a difference between the low trim shutoff and low throttle (high trim position). You really can't mess it up, cause if you enter a trim value in that is out of range, the ECU will not learn it. Once the high trim is learned, the ECU linearizes the remaining range you have from high trim to full throttle. You loose a bit of throttle resolution but that is completely irrelevant in what we are doing.

But remember if that throttle trim switch is glitching, no matter how large a difference there is between the low throttle trim shutoff and high trim, you are still going to get a shutdown.

Did you program the PIC? If so you might want to add some low pass filtering to the pot input.

Good luck,