Question Fuel pressure fluctuations in flight (fuel pump off)

[Neal]

Found it. Attached.

 

[Cactus Charlie]

Has anyone ever found any significant contamination in the Andair filter?

I have never found any and don't see how it is possible if the gascolator is clean.

 

[Neal]

I was wondering that, didn't want to ask. Risk of messing with the fuel system vs. findings in the filter. Probably not something I'm going to do as anything that can make the engine stop is not something I touch so it will be my local A&P to do.

 

[ve6yeq]

Has anyone ever found any significant contamination in the Andair filter?

I have never found any and don't see how it is possible if the gascolator is clean.

From what I have heard, the gascolator screen catches the vast majority of contamination, and if the gascolator is clean during the 100 hr inspection, you can skip checking the Andair filter. However, as the Andair filter is finer than the gascolator, if you find anything in the gascolator, you should also check the Andair filter.

Personally, I have never found anything in the gascolator other than a couple of small drops of water, which I think are from condensation because I do not always refuel to full after every flight.

 

[Cubonaut875]

Interestingly, right before my ignition coil failed, I had a lot of spurious fuel pressure readings, tested pressure all normal. Then the coil failed, replaced the coil and then all the fuel pressure fluctuations normalized. Maybe a coincidence - just throwing it out there.

 

[Neal]

I have exchanged several emails with Brandon Dildine at

Technicalsupportn (Lycoming)<[email protected]>

He has always been helpful and supportive. I do no know what discretion he may have on warranty claims.

The parts in the fuel pump that could fail are the diaphragm, the inlet valve, and the output valve. I doubt any of these would have failed at such a low time. I would expect contamination intermittently preventing sealing of the input valve.

Perhaps Lycoming will take an interest in this early failure and offer an exchange part. Send your data to Lycoming and ask for support.

Well, I emailed this address when you provided it. Nothing heard to date, sadly.