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Getting an* by EGT. Below allowable start.

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Getting an* by EGT. Below allowable start.

Old 12-15-2006, 12:02 AM
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Default Getting an* by EGT. Below allowable start.

I have a PST J600R and have started it once on the bench. For the first few times it did not start. My thermocoupler was bad. The GDT was reading 979c. So, I just received a new thermocoupler and hooked it up and now the temp on the GDT says I think 24c. Now the turbine is in my boomerang. Anyways I know the propane is ignighting. (I can hear it and I know what it sounds like and the little red light is on on the solinoid) The turbine also spooled up to 19,000 rpm (while the propane was flowing through the turbine) and just stayed there for almost 5-7 sec. then shut down. After 4 starts my GDT says "start fail" and also shows an * on the right side for EGT and an * on the left side for shutdown. When I first got this engine it would not start. The GDT said the temp was 979c. I would get a start fail. So I tighten the screws on the EGT probe and the GDT said the temp was ... I forgot but it DID NOT say 979c and I tried to start the turbine again and it fired right up! Kelly I might have to send this to you... Also I am going to take all the pluming out of the boomerang and run the turbine on a test stand again.
Thanks, Mario
Old 12-15-2006, 02:06 AM
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Default RE: Getting an* by EGT. Below allowable start.

What temp is the turbine when its spooling on gas? The EGT has to reach 110 deg before it will start the pump. Try another start and watch the GSU, if it dosnt reach the required temp open the gas valve a little more.
Old 12-19-2006, 11:24 AM
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Default RE: Getting an* by EGT. Below allowable start.

NEVERMIND! I got it running! I took all the plumbing out and put the engine back on the test stand and it started right up! Now its back in my boomerang (with better plumming routing) and hopefully its starts right back up!.
Thanks, Mario
Old 12-23-2006, 09:50 PM
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Default RE: Getting an* by EGT. Below allowable start.

Woah, Sorry Mario. I just noticed this thread today...[:@]

What you describe sounds like it could be a kink in the fuel line, plugged filter, or a sticky pump. Redoing the internals can often cure this. Next time you run the engine, make sure to slowly raise the throttle and do a full speed calibration, since the ECU may not be accustom to the decreased pump voltage requirements with lower restriction.

If it lights on propane and fails as you've described even after you've checked for restriction, it may be a sticky fuel pump. the quick cure for this is to close the ball valve, then give the pump a quick shot (~1 second or so) with the ECU pack directly. A new (or very old) pump may rarely need this, but if the pump is well used it may be time for replacement. Either way, you should hear it spin up right away on the ECU pack.

If it was driven by an EGT problem in the start sequence, it typically means that the EGT has exceeded the minimum start temp (default 110C), then fell below it again. That's a sign of a start fuel problem...

Just for those interested...
While shorting the pump as described above, if you hear a loud 'tick' noise and no spinning, disconnect the pack immediately! The pump is locked up (ie. toast...) and you're shorting the pack over very little resistance, which may or may not damage your ECU pack. I've only seen one pump do that though, and it was one of my own fresh out of the box.

Glad to hear you got it running again without much trouble. Merry Christmas / Happy Holidays!
Kelly

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