Hi everyone, sorry to resurrect an ancient thread. If there is a better place for advice, let me know:

I've got an old JJ1200 KIT that I got in probably 2007. It has the "semi auto" Regal ECU. I start it with a blowtorch and an air compressor. If the firmware is update-able I have not done it. I ran it a few times back when I first got it, I recall feeling it had ECU issues, I shelved it and only picked it up again recently. I am having an issue with it flaming out when I approach the high end of the RPM range. The ECU reports speedlow then flameout. I strongly suspect the problem to be the hall effect sensor. After running it, it is commonly reporting an RPM of 6600 with zero rotation. It continues to detect rotation, just is then wildly wrong. I think when I approach the high end of the RPM range a glitch in the RPM signal is causing the ECU to sense an impending overspeed so it cuts fuel, and way too fast, causing a flameout. Or possibly the sensor glitches to show a momentary zero rpm and it detects that as speed low and flameout. I'm not sure, but I am pretty sure its not ACTUALLY flaming out as it cuts out instantly and I don't get that tell tale white smoke trail of unburnt jet fuel for a few moments. Interestingly, when the engine is running the RF interference must be bad as my FrSky telemetry cuts out frequently. I'm running on a 3s lipo, with a BEC providing the power to the receiver, then a male to male servo lead going to the ECU. So I believe my BEC is powering the ECU. Everything is connected to the same 3s lipo. As I'm typing this I am realizing that could be the cause of all the RF interference. Maybe I should try a 4.8v NiCD.

Things I have done:
-Removed and re-installed the hall effect sensor checking for issues. Found a standoff spacer slightly too small so it wobbled just barely. Fixed, now snug
-Applied a strong magnet to the hall effect sensor hoping to make it stop reporting 6600. Did not fix. The 6600 seems to be intermittent
-Tinkered with the deceleration delay from 15 to 25. Problem persists.
-Calibrated my throttle range in the ECU
-The max rpm is currently limited to 140,000 so I don't wildly over speed it if something happens. It only seems to happen near the end of the throttle range, not necessarily approaching the actual 160k limit. I wonder what happens if a value is sent beyond the calibrated throttle range? Would that cause a shutdown? I may tinker to check that.
-I have disconnected the RPM sensor while the engine is running to verify the behavior. A nearly immediate shutdown with a speed low and flameout message, leading me to believe this is definitely related to the speed sensor.

Any suggestions or "must do" items to get this engine running smoothly? Even not related to this problem. I'm not afraid to take it apart, I am very mechanically and electronically inclined. Even building my own ECU is not totally out of the question, but I'd rather spend my time on other parts of this larger project.

Thanks!