LMilner

I have a brand new JetCat P-180 that is having startup issues.

Two different symptoms, probably related:

1. It will start, Stabilize and learn low. When you try to increase the throttle it will not go above 5200 rpm and produces almost no thrust.
2. It will start and begin to ramp up but it will flame out while at "Stabil". Off code is "LowRPM". Flames come out the tail pipe.

Conditions are hot and humid here in Atlanta.

Things we have tried w/mixed results:

1. Checked fuel system, looks ok.
2. Restart and relearn RC.
3. Set IdleThrResponse to : Normal & set FullThrResponse to : from "Fast" to Normal. I was advised this helps in hot and humid conditions.

The engine has 4 flights on it. It did this a previous trip but after several restarts it ran normal.

Any suggestions?

Dave Wilshere

What is the pump figure at idle? And any idea what the full power figure was?
once it’s running at idle, try opening the throttle really slowly in steps, does it accelerate through then?

Have you every done a reset to clear figures stored on the ECU/Front boras and pump? It will clear the log and go back to factory. Same as learn RC, just keep holding the button down.
Last what software version?

Dave

dccatl

My Feedback: (1)

Dave,

I was with Lanier yesterday when trying to start his engine and want to clarify a couple of points:

Regarding issue #2: It did not "flame out" during the Stabil phase, rather produces an excessive amount of blue flame out of the tailcone resulting in the smoke nozzles installed just aft of the engine glowing cherry red. This was the issue presented on the last 3 starts attempted, one of those the ECU aborted due to over temp and the other 2 were aborted manually and fuel shut off. On all three attempts the engine never left the "Stabil" phase.

The first issue (lack of full throttle) occurred during several earlier start attempts, finally after performing a learn RC and attempting a start we were able to get the engine to respond normally by slowing increasing the throttle after the "Learn Lo" status and letting the RPM stabilize at the commanded RPM at multiple points during the full run range - at full power we observed a message to the effect of "storing pump values". The engine was then shutdown, the plane prepped for flight and on the next start attempt the excessive flames occurred as described above.

Idle pump power was about 1.3 and during the instances that there was no full throttle would increase to about 1.5-1.7 at about 50-52K RPM which was as high as it got.

To summarize: currently the excessive flame during "Stabil" phase is the primary issue. We did not try a reset as I don't know much about Jet-Cat (except to advise Lanier to post here and get your advise) and wasn't sure how to perform. Lanier would have to get the software version. Also note we only had the mini-gsu installed in the plane and did not have access to the interface board to be able to connect the full size GSU.

Dave Wilshere

OK. An idle of 1.3 (cica 33-34,000) is really high…should be 0.7-0.8 max. If you have fuel restriction the pump is going to be working really hard to try and supply fuel.

Mini GSU gives you all the info the full size one does. You can even look at some of these figures. Hold the select menu white button and scroll through.
Is the turbine an Rxi?

Dave

dccatl

My Feedback: (1)

Dave,

Turbine is an NX model. Fuel system seemed free of restrictions, high flow fittings and 6mm fuel line, I guess pump is inside the engine. Not sure what’s inside the tank though. Will have to go through it before next attempt to start it. Will try a reset as you suggest as well.

Thanks,
David

LMilner

David thank you very much for adding your input.

Dave, I will reset like you suggested and see where that gets us. Thank you very much for you insight.

Lanier