Hello,

Just some comments on setting up the 44s:

The main problem on tunning this engine is that a high voltage battery is used to allow the starter to have enough rpms to reliably start the engine. The pump is very powerful and only need a couple of volts to run the engine at full power, so the 80% of the regulation margin of the electronics is wasted reducing the battery voltage.

At idle the pump run very slowly, so it is very unstable in its RPM (pump rotor rpm I mean). Usually a 1/1000 of voltage change on the pump cause a significant rpm change in idle RPM of the engine, making very difficult a reliable regulation. Also, the drag and performance of different pumps is very noticeable at these low pump speeds. I mean that at, say, 3V all pumps pump approximately the same 200ml/m (+/-25ml) and differences are very small, but at idle (0,2V) at bit more sticky pump can flow half of fuel of another, making a big difference in engine RPM.

Some tips and clarifications:

-Acceleration: The MW44, if overfueled in acceleration, usually flames-out. Bigger engines raise the EGT well before suffering flameout or combustion instability, so the ecu can "see" that it is pushing too much the engine and take the appropriate actions. On the 44 usually the ecu don't see anything until too late.
So, if the engine flames out in acceleration, increase the "accel delay" until the acceleration is stable. Values of 40 and higher are usual.

-Deceleration: Here the 44 behaves different too. A too fast deceleration cause the combustion chamber too cool down and the RPM undershoot the idle settings. This undershoot can cause a flame out, but usually what happens is that the ecu reacts raising the power of the pump at idle (calibrated at startup). This higher value cause the once the engine stabilize internally and the combustion chamber heat-up, burning better the fuel, a increase in idle RPM.

-Stability: Lower number, less stable is the engine in rpm. Use a value of 100 or higher.

It is very difficult to keep a stable idle on this engine, and a change in 55k to 58k don't have any influence on flight. The thrust change is of 0,3N (0,065lb).

About the engine landing on a high idle, can be different causes, for example a incorrect mix on the transmitter that modify the idle value, but specifically on the 44 I would think in 2 main possibilities, either easily identifiable after the flight. One is the problem of engine undershooting in deceleration, as previously commented. The second is related to fuel installation that cause that the pump should work harder to pump fuel when tank full than in empty (tanks in series, etc).
To diagnose, the best is to download the data from the ecu, but if you don't have the cable, you can do it "manually"

First you should annotate the values of power of the pump (value under the temperature reading) at idle after starting the engine and the throttle percentage (value at the left of the "pulse=xx" reading. After the flight, when the engine show the 90Krpm, and before shutting down, check again these 2 values.
If equal or less, then the problem is related to fuel system (pump, tanks, etc) that modify its delivery from full to empty (or the pump is too draggy at cold).
If the Pw of the pump is higher and the throttle percentage is the same, then the engine had its rpm under the minimum in any part of the flight. Usually a too fast deceleration.
If both values are higher, then the problem is in your TX.

DO NOT install a restrictor in the fuel line, this will overload the pump and the electronics, the amperage of the pump will raise a lot at full power, increasing the wear on the pump and using a lot more battery. What we need is to have the pump running faster at idle to have more stability, and a restrictor put the load at full power, not at idle. What is a very good solution to derate the pump at idle is to install a adjustable bypass. This is simply a "T" fitting in the line from the pump to the engine, with the 3th output going to the fuel tank (or to the pump input via a second "T"). The return line have a adjustable valve in series, so that part of the pumped fuel can be returned to the tank. This allow the pump to run a higher speed at idle but with same back pressure, and at full power the pressure at the pump output is the same as without this bypass, so no extra load is placed anywhere. If any of you want to try it, I can explain how to adjust the bypass valve, but now I'm a bit in a hurry.

Regards,

Gaspar