JBrickey

Recently my Wren 44's fuel pump stopped working. When attempting to start the fuel ramp up message appears, but I do not hear the fuel pump run and no movement of fuel can be seen.

I've been able to verify the pump works by direct wiring the battery to the fuel pump. When I direct wire it, it pumps just like it should.

Do I have an ECU problem possibly?

My Cadnica 3 cell battery back displays 3.910 on my volt-meter (is this a correct reading) it seems to run the pump awfully fast when directly connected!

I've also tested and verified a full charge on my receiver battery as well.

Are there any tests that I can run before I send this off to Wren?

Regards,
J.

gooseF22

before anything, recheck connections, especially the pump/solenoid, and rpm sensor are plugged in correctly and you are reading rpms when the motor turns over. Make sure rpm isn't backwards.. make sure propane solenoid isnt in the fuel slot. seen and done it..

JBrickey

Good idea Goose! However I've already done that and I just had it running today.

Nothing has been unplugged or disturbed since the model was built 4-5 months ago. It's also been flying every clear weekend since finishing it. All of the connections are solid and in place... very odd

The RPM and Exhaust Temp are both functioning. When heating up with PowerMax and the temp reaches 100F the message displays (as always) FUEL-RAMP and the little green light starts flashing... but no fuel pumping... like I said, if I hook up the fuel pump directly to the battery, it pumps like crazy. I am thinking it could be in the FADEC itself, however I would like to hear something from Ron on this one and see if he has any testing suggestions.

Regards,
J.

Wren Turbines USA

My Feedback: (39)

Morning J.,

First thing to look at is the "minimum start temp"... on occassion, I have seen this parameter accidently get changed..It should be between 100C and 108C.
Next, inspect the solder connections at the plug and the connector on the ECU. If these check good...my guess would be the ECU. I can overnite you a loaner while yours is repaired. Email me your shipping info, along with the serial# of the motor, and I'll get one boxed up this morning.

Best regards,

JBrickey

Good Evening Ron,
It turns out that after replacing my ECU it runs like a top... I borrowed one from a local shop that has a used Wren for sale. Am I allowed to clip some of the heat-shrink material away on my faulty ECU in order to look at solder connections? I have a feeling that maybe a connection may be at fault and it's hiding behind the heat-shrink. If that's the case, I will re-solder and be back in business. If it's not the problem, I will be sending it off for repair.

Best Regards,
J.

Wren Turbines USA

My Feedback: (39)

J,
Glad you have found the problem!

Feel free to investigate, and as stated earlier, I have loaners to keep you going, if needed.

cheers,