Guys

I had a couple of flights today and it always took a couple of trys to get the turbine to run. Finally it would not start at all. Acceleration was the problem - it would get to about 30k rpm and switch off. The battery is fully charged. The bendix does seem a little stick but seems to engage when I test run it. This engine has less than 3 hours on it.

Any ideas please?

Have you checked if the fuel is ramping and what is the egt during start up?

Remember that the outside temp is a bit low right now, so keep the gas bottle warm or switch to propane, I would also check the fuel filters if the fuel is ramping correctly.

How full is your gas canister?

How warm is your gas canister?

I believe that in the cold temperatures at this time of year these are quite important. If you haven't done already, I would try taking a new can from inside the house (where it is warm) and giving it another go. If it starts fine then you know where the problem is.

I had a similar problem with my Jetcat before I learnt how much gas to use and it would start to ramp up on the gas and then stop (fuel ramp had not started sufficiently).

Just a guess though. I'm sure someone more experienced than me will be able to help more.

Sounds like the gas is to cold
keep it warm until you need to use it, had the same problem

Guys

Thanks for the input. You replies have prompted me to update my personal information from location = UK to location = Qatar (Arabian Gulf).

It is warm here even for winter about 24 degree C so I don't think temperature is the problem. The EGT was getting to about +130C before shut down - I did not take note but that was more or less where it satrted cooling from and was higher after a few failed attempts.

How do I determine the fuel ramping ?

Thanks

Rory

With a EGT of only 130c it doesn't seem like it's burning fuel.
Maybe your fuel pump is sticking...?
Try to look at the fuel lines during start-up if they are transparent. Sometimes a little knocking on the fuel pump with a screewdriver/ wrench helps.

OOPS sorry Rory did`nt look to see where you live
sounds like its slow to ramp up are the batteries Ok (have you got a cell down)

Check the fuel solenoid is not sticking.

If its getting to 30k then the gas is working right!!!!!!! Most motors can only spin up to around 20k I believe, and would think if its sticking it may have been part open explaining the slow acceleration as the pump would be unable to keep up the demand from the flow.

Not sure on the jetcat if you can put a couple of volts across the fuel pump in situ and see if it, well, sucks!!!!

Let us know!

Gazzer

Solenoids and fuel pump can be tested using the GSU.

The fuel pump is working - I checked the pump voltage for start up. I thought that it might running too fast. I will check the fuel solenoid tomorrow! I did notice that there seemed to be a burning noise coming from the unit while it was cooling down after a failed start.

If the noise you are hearing is a crackling noise from the turbine, it is unburnt fuel boiling away.
Check all the settings of the turbine with your GSU to see they are ok. I had an ECU that became corrupted & the turbine would not start.
Clean all the fuel filters. Check the vent pipe to your fuel tank is not blocked. Disconnect the fuel supply to the turbine & run the pump manually & check the fuel flow.

Regards

Allthough I fly a differnt brand of turbines, I guess the problems are the same, and mostly the solutions are the same as well. If I experience a problem like this, I would check my fuel filter right away. Next think I would do is to check that the fuel can run freely throught the whole system. It could be anything from a stuck solenoid to a stuffed felt clunk in the fuel tank.

If the propane ignites and the fuel can run freely, the tubine will run if the fuel pump does.

I have had the same problem with my P60 usually on the first start of the day. After that it usually starts without a hitch. I put it down to a sticky fuel pump as it is relatively new. I fly in warm temperatures...up to 30 degrees C and always make sure that my gas is filled 1/2 hour before I fly to allow the cannister and its contents to reach ambient temp so I don't think temperature is the issue here. I tested my fuel pump outside the model but I would assume that the ECU would shut down the engine if the rise in RPM during start is inconsistent with the supplied pump voltage. The supplied pump voltage might not tranlsate into proportional fuel flow if the pump is sticky though, and this is hard to judge without some accurate standards and measurements to work with.

For some reason my P-60 eats glow plugs and I get the same symptoms. Try changing the glow plug and I'll bet it fires right up.

Jerry

In fact the glow plug came up as a problem so I replaced it at the field but, I still had the same problem. We have 4 days of holidays this week (Qatar) so I will check the pump tomorrow and report back.

Thanks for everybody's input.

I would think if the propane is lighting then the glow plug would not be the problem, Are you sure all the lines and electrical plugs are in the proper order?? The reason i say this is my freind had a P-80 that he could not get to start properly,, Turns out he had something plugged up wrong.. Russ

How about posting your question in the JetCat turbine clinic forum. You will get reply directely from JetCat.

http://www.rcuniverse.com/forum/forumid_151/tt.htm

Hi again.

I did post on the turbine support thread and got input from MrMatt.

I increased the gas from 60 to 70% and also increased the pump start up voltage slightly (I had fiddled with it at the field thinking that there was too much fuel coming through but it was now way too low, but I have now set it to one click more than what my original settings were). It seems to be starting Ok now. Don't know if it was the gas or fuel though.

The only thing I notice is that when the starter motor engages, it is quite noisy compared to what it used to be. Could the bendix need cleaning ?

Once again thanks for the help.


Rory

Ask the question again in the turbine support forum for a better answer.