Mark,

I had a similar problem with my brand new P120SX just last weekend, where I had many failed starts (ignition timeouts) before the turbine finally started. I managed to start it for the second time, but once again only after many failed starts. The pump start voltage U-accelr1 was increased at increments of 0.025V and had reached 0.35V before the turbine started.

As many have already suggested, both fuel lines were disconnected from the turbine and the pump was run. This is quite easy to do if you wish to run the pump for a few minutes, simply go to Menu=>Test Functions=>Purge Fuel System and hold the Change Item button. I found the fuel to be flowing without any difficulty.

Another attempt was made and once again it failed (ignition timeout), a further 8 attempts were made before it ignited and ran for the third time. The pump start voltage was now at 0.4V and when it switched over to fuel valve … too much fuel! At this stage, I was certain it was not the fuel pump.

On all attempts, I ensured there was sufficient power in the ECU battery (LiMn 3600MAh). I also checked the filter and the hopper tank and both were clean. The burner was glowing well, both solenoids were working and installed correctly etc. Also, the turbine ran fine once it started.

After several more hours of troubleshooting and with the assistance of INTAIRCO and 2 experienced jet flyers (Blackcat & Highflyer) we eventually found the cause of the problem. Fortunately, a bubble was in the burner fuel line and during another failed start-up, what we observed was an inadequate amount fuel flowing into the turbine; the bubble had moved downstream slowly but then commenced to move back upstream after the failed start. We determined that there must be a partial blockage inside the turbine; somewhere inside the turbine, between the 3mm festo fitting and the burner. There was insufficient fuel reaching the burner to allow for ignition.

A friend applied a vacuum to the line and “pop” it was cleared. We don’t know what came out, but I suspect some residual braze inside the burner feed tube or swarf from the burner solenoid valve moving downstream and lodging itself inside the turbine.

The pump start voltage was then lowered back to the default setting of 0.2V and the turbine started without a problem. Several subsequent starts have since been made and the turbine starts and runs flawlessly.

Can I suggest that you take a very close look at the fuel flowing into the burner valve with the fuel line connected to the turbine? Do this by going into Menu=>Test Functions=>Burner Valve Test.

Also please be aware of the following test functions:-

[ul][*] Burner Valve Test- Runs the fuel pump and opens the burner valve (clicking). [*] Fuel Valve Test - Opens the fuel valve only (does not run the fuel pump).[*] Purge Fuel System - Runs the fuel pump and opens the fuel valve.
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Perhaps you have the same problem. If not, then I hope the above has been of some help to you.

Good luck with it.

George