yf222000

My Feedback: (6)

Hello.

I am wondering if any of the experts here have seen this problem. The engine was working fine for a long time.
Now, as the turbine spools up from a stand still, the fuel pump kick in and trying to prime the fuel system, but
the pump only turned over very little and then stop. Sometimes it would continue to run for a short while just
long enough for the glow driver circuit to switch on as the manual says. But this is very rare and even if the plug
lights up, the pump will stop which cause everything else stops. I have tested the pump with a AA battery.
The pump runs smoothly with that AA. Does anyone might have an idea why the engine is doing this? This is
an old air start (Auto Sequence) Simjet turbine, which has run so smoothly for a long while before this bug shows
up. I thank you all much for the inputs and help.

gooseF22

do you have a GSU? what does it say. I would suspect a glow plug first.. then an rpm sensor

yf222000

My Feedback: (6)

Hello.

Thank you for your reply. No, this is an old model, so there's no data terminal at all. I am suspecting the RPM board too, but
I really don't know. The glow plug circuit is working correctly according to the manuals. Sometime the pump would prime fuel correctly
so that the glow circuit would switch on, but that's where all things stops. Other times, the pump would just barely turn over and
then just stop there without going any further. It seems like the RPM sensor board doesn't read the compressor's rpm correctly or
consistently. The manual says that if the compressor speed dropped below a specific RPM, the start sequence will stop. The "start" abort process
begins with the pump stop priming the fuel system to get rid of bubbles in the line, then the glow plug circuit would stop after that. So, because
the pump sometimes worked correctly up to the point where the glow switch on, then fails, makes me think it is the RPM sensor board failing
intermittently. This engine has very low time. Maybe 3 hours altogether.

Jetpilot24

My Feedback: (21)

Check your fuel filters. Make sure that there is no blockage in them. In line filters, filters in the tanks. If that is not it check all your fuel lines make sure nothing is kinked or pinched. If that isn't it, I would think you have a pump going bad. I had a similar situation. Pump would work fine on AA battery but on the motor it wasent turning fast enough to pump the fuel in. I changed the pump and everyting was fine.

The pump I had a problem with was a Flight Works. I switched to a Haussel pump.

Joe

racer8297

My Feedback: (13)

Not to be a PIA but aren't you the same guy from the Simjet forum? Kerry gave you some advise and a big offer of help. What ever happened with that?

Jim

yf222000

My Feedback: (6)

Hi Jim.

Yeah, I am the same guy in the Simjet forum. I posted the question here, not because Kerry doesn't know or
incapable of helping me, he is still working on helping me. There are many knowledgeable veterans here
too, so the more inputs these experts could give, the more i will learn from them. That's why i liked this forum
because the wealth of experience they have. I don't know everything, so I'd thought I ask here. If anyone could
help, I thank them, and if they could not, I thank them anyway.

yf222000

My Feedback: (6)

Hello Joe.

Thank you for your help. I had replaced the pump with a new one from Jetcat, since it is of the same connector and
rating. The things that made me pulled out my hair is that, it was running fine just two weeks before. From the last time
to where this problem showed up, I didn't start it, or do anything different at all. Just pow, stops working.

Jetpilot24

My Feedback: (21)

Could be an ECU issue as well

yf222000

My Feedback: (6)

I am hoping that it isn't, but may as well could.

FILE IFR

At this point it is likely not an ECU adjustment so there may be nothing more you can do.
Kerry is sending you a thermo coupler as he is near certain that is the trouble. If not, he thinks it will be the RPM board.

Give Kerry a chance to bail you out without sending the turbine in.

yf222000

My Feedback: (6)

Oh, definitely. I am not saying that he couldn't help in the earlier post.
I was just trying to explain that Kerry is still helping me big time. I just thought that
i would ask here, since there are a lot of experienced gents here too. It
is that reason why i liked this forum a lot. So much info and assistance
came from here over the years, and i thank you all for that.

Jetpilot24

My Feedback: (21)

YF
Let Kerry help you through this. He has helped me in the past greatly. He is good people

Joe L.