Hey Jeremy,

I replied by email shortly after you sent it, but for the benefit of everyone else here's my leading suspicion(s).

This sounds like some sort of fuel atomisation problem. Its really tough to say, but I'd bet its not related to the ECU or any sort of hose routing, fuel pumps etc... If one or more of the injectors is clogged with debris not functioning properly and fuel is somehow pooling in the engine at low throttle, the increased mass flow could pick the fuel up and inject it late in the combustion chamber. That's a pretty wild guess though.... The flame may also be quite irregular is an injector or atomiser tube is not healthy...

If the flame moves external, the differential pressure over the exhaust turbine will be reduced, which then causes the compressor to slow down while the fuel rate is increasing. Before you know it, you've got a chicken and the egg scenario where EGT is rising, RPM is falling, and its going to shut down from one or the other. If fuel isn't pooling, it may just be a really imbalanced flame... If anything its to blame, its likely something inside the turbine core. 1st thing to do is check all your filters to see if you can find any signs debris entering the fuel system.

I have an email off to Thailand looking for their input. I'll let you know when I hear back, or perhaps Kraivuth may weigh in with his comments directly.

Kelly