JimJones1

Had an odd thing happen with my P20 today:

Started ok (Gas Start) Took off fine. Then I throttled back and the turbine went to idle and then would not respond to the throttle at all. Landed ok

It responded to the trim to shut down.

Then it cooled down and was ok. Switched off and then went for a start. It started fine and the green light came on but it would not respond to the throttle

Stopped it and let it cool down. Then unplugged the ecu from power and then started again. This time it worked fine and responded to the throttle.

Any ideas or has any one else had this ?

warbirdfanatic

My Feedback: (1)

No experience of a P20 but it sounds like a lead connection if you unplugged it and then it ran fine? Are the pin outs ok? I've seen quite a few damaged ecu's because the pins have pulled away from the PCB. Give the ECU a shake and listen for any rattles (signs of a cap coming loose or damaged)
What was the state of the battery? This could also be a symptom as batteries can wind up the ECU something rotten!

bidrseed2

My Feedback: (2)

Last summer, i started my gas start p20, it didn't sound particularly happy.
When it stabilised at idle, it sounded like it was in a locked in surge, and wouldnt respond to throttle commands.
I shut it down and tried again.
I spoke with Uncle Dave of motors and rotors, and he suggested changing the plug, they apparently have a hard life in the smaller engines.
Its been fine since.
Its and inexpensive thing that you could try and report back.

JimJones1

Thanks for the feedback. Which plug are you refering to

BaldEagel

The only plug accessible to us mear mortals, the one on top of the turbine for the ignition.

Mike

Henke Torphammar

If it starts it doesn't sound resonable the plug is out.

Henke Torphammar

The solenoids are very small and do jam from time to time. Try bypassing the fuel solenoid and see if it helps.

JimJones1

There are loads of other plugs, The Power lead plug. The io Board, The plug to the valves, The pump to name but a few

BaldEagel

From Birseeds post the only conclusion would be the glow plug, but then again you have 16 turbines you must know more than most of us Dennis.

Mike

JimJones1

Henke

Thanks for that suggestion but I dont think it was one of those that jammed as The turbine was still running it had just lost all throttle command on the main stick but did respond to the trim as it would shut down

The glow plug thing is I think a red herring as it just blew shortly after the last start once I got it runnign ok.

I think I may well just put this down to a scrambelled ECU for a short while

Thanks to those that offered some useful help

JimJones1

Ah thanks for that Birdseed I see now that you meant the glow plug. I was thinking one of the electrical connection plugs to the various pieces of equipment. Looks like I had a brain fart as well

BaldEagel

warbirdfanatic

My Feedback: (1)

It's quite common for a plug to be erratic, then again, if you had a solenoid lockout this would stop any fuel from going through but would still allow trim as it's just a command, if the fuel can't get through then the engine will go nowhere. I had a few plugs go on my jet joe and this was overcome by adjusting the glow power in the ecu settings. Best of luck getting it fixed mate, fingers crossed we'll get a summer in the UK this year!!!!

Dave Wilshere

Not glow plug in this case, but they do need to be a cooler (thicker element coil) for the P-20 which has a smaller chamber and higher internal temp at the plug.
There is odd P-20 software bugs, you not switched ECU's or pumps between turbines? Or new bought parts for install kits?
The P-20 more than any JetCat turbine needs the three items updated together to keep the harmony...

Dw

JimJones1.

Dave

Thanks for the help. Yes I have swapped over some components after I had a pump and ECU failure which I sent back to Jetcat. The combo I have in this plane has however flown several times without problems. I will have to try it out again (perhaps today) to see how it goes

Thanks again