Hi All,

I went flying today and after the first landing starting to taxi back to the pit area my P-80 just stops, on the second flight the same ting happen. later I just taxi the roo few times up and down the runway, wit out any incident.

Does any one has an advice of what may caused it, the hand device showed low rpm -last off condition.
I have 57 flights so far with the p-80.

Regards,
Richard Mattenberger

Hello Richard,
I am no expert Jet Cat person, but I have owned a P-80 for several years now. Three or Four times over the years the very same thing has happen to me. Only while taxing, never while airborne even considering the fact of course at times the throttle has been reduced to idle during approaches momentarily, good thing it never quit then --- but it hasn't......
If you connect your GCU box to the ECU, start your motor go to the screen that allows you to watch RPMs, then throttle up & down a few times. You will notice there is a sag in RPMs below your default setting of 33,000 momentarily. I believe the newest versions of ECU programing has a delay time built in before automatic shutdown occurs if RPMs go below about 28,000 RPM, that the eariler versions of ECU software didn't have. Matt or Bob of course could answer your question better than I. You might try adjusting the idle up to 34,000 see if that changes the bottom end sag RPM's.
Lee H. DeMary
AMA 36099

A friend of mine has just started into jets. He picked up a used jet with a brand new p-120 in the box with it. On flight nine he had a beautiful landing, came to a stop to turn around to taxi back and the turbine had shut down. He tryed to restart it again but the propane tank was empty. By trying the restart it cleared any info in the ecu, so we don't know why it happened. He has at least 10 more flights since then and no shut downs that he has said. Sounds like an ecu problum not an turbine issue.

Hello,

Lee is probabaly right, you need to have the firmware updated in the ECU.

If you plug in the GSU when you switch on the model, it will show a "revision" something like "4.9Q" or something like that. Can you do that and then write back what the display says? It will tell how old the firmware is.


Thanks

my 4.0 did the same thing but in flight downwind, came up short of the runway and bent the nose of my roo on its maiden flight...

get the ECU updated and FLY with confidence

Matt,

The GSU shows "Jet-Tronic 2.01U" and "Ready <CAT 2001>"

Regards,
Richard

Hi Richard,

That is a pretty old ECU, we discontinued the 2.0 version in the USA a couple of years ago.

It is funny why this would start after 57 flights. I would check the fuel system. Can you look through the menus and see what the last pump voltage was at shutdown?

Regards,

Matt

hi matt
How do I upgrade my version 2 ecu to the latest?

thanks

Hi Matt,

Last pump voltage at shut down shows 1.1 volts, how ever, yesterday at the field I did start the turbine one more time to do some test taxing the roo up and down the runway to see if the turbine will quit again, but it did not, so I shut down the engine myself, but I remember that when the turbine went off by it self I am almost sure that the last pump voltage was 1.0 volts.

Thanks and regards,
Richard

Hello,

THere are no updates to make a 2.0 into a 4.0 or now the 5.0. It is a direct replacement. It is less of an issue if you do not fly on 72 MHz, although the 4.0/5.0 are dead quiet on all frequencies.

Hi Richard,

This off voltage is too high, we would expect the shutdown voltage at idle to be about .6 volts. There is definitely a restriction in the fuel system, which also explains why your plane flew fine for 57 flights. I would backflush all filters and check your UAT if you are using one (or any kind of filter clunk or felt clunk). High altitude may also make the motor somewhat more sensitive to this, but it is definitely a restriction. Did you notice what your full throttle voltage was?

It is a good practice to always keep track of your high throttle max pump voltage. It will reach a normal level (anywhere from 2.1 to 2.7 depending on many factors). As the fuel system begins to clog, this voltage will start to rise, maybe .05 volts per flight. That is a sure sign of rapid clogging. 57 flights without clogging is pretty good, so once you clean everything out you will get another 40 or 50 flights, but keep track of that max throttle pump voltage!

The 2.0 ECU is OK if you are not on 72 MHz. But I would still recommend upgrading to the newest ECU.

Hi Matt,

How much will it cost me to replace my old ECU with a 4.0 or 5.0 version? I dont want to fly till I have the new ECU, I think it is not safe any more, I fly with 72 MHz channel 28 radio. Do you have one ECU 5.0 for sale for me? What else can I plug in to the new ECU? GPS? Speed Control? Prices please.


Thanks and Regards,
Richard