Status update on the troubleshooting.

After sending Gaspar both the Jeti TM logs and the ECU data download, he suggested that there may be an issue with the ECU, so he shipped me a replacement ECU via 2-day UPS. On receipt I installed it, but no change, still getting the rpm drop exactly as before.

I then hooked up an external fuel tank, new receiver and ECU externally to the model and ran the engine, trying to isolate any installation issue and I saw the same rpm drop. Next, I swapped the turbine for another M140 from another model which I know runs fine, and again saw the rpm drop. At this point, the only remaining common item left was the fuel pump.

After sending Gaspar this latest information, he agreed that the pump was most likely the cause, and he shipped me a replacement pump, again by 2-day UPS from Spain.

Well, tonight, I swapped out the pump and did another ground run. No change!!, still getting the rpm drop exactly as before.

So, in desperation, I made a test stand where I could run the engine away from the model. With the old pump and direct fuel feed to the pump, the engine ran fine, holding 130,000rpm indefinitely. At least some progress at last!!

I've started to add back into the test stand individual parts of the system as installed in the model and I have again observed the rpm drop when using the model installed radio system and ECU, connected to the proven good external pump and engine on the test stand.

At this point I think I can prove that it is a model electronics issue, but I have yet to isolate the actual source of the issue.

More updates to some - I think I'm getting closer to solving it.

Paul