Fuel pressure reading high

[FlyDave]

Flying home last night I was at 11K for 1h 30m and I noticed my fuel pressure gage reading in the red (see attached picture).

I didn't notice this until I was up at altitude and it continued for the duration of the flight at 11K. As I descended to 9K, then 7K, FP moved back into the middle of the green arc on the guage where it usually runs.

The other thing I noticed was that my FF was at 10.3 gph when it would normally be aroung 10.6-7 at that altitude.

Any ideas on what would cause this higher fuel pressure or is it more likely a bad fuel transducer?

Thanks for any input!

[Piloto]

I had the same readings before and after engine overhaul and it didn't bother me. If you look closely when this happens the meter needle does not rest at zero when there is no pressure. I think the problem is due to an offset on the fuel pressure indicator.

José

 

[FlyDave]

Jose,

Thanks for the response.

Attached is a picture that was taken about a month ago. This is where the fuel pressure has been for the last 14 months that I've owned the plane. It seems something has changed.

When you experienced the higher fuel pressure before and after a rebuild, did it go up from a "normal" position or was it always high?

Thanks,

[Magnum]

If you know a bit about electronics, you can build your own test plug (see attached pictures).Connect it instead of the transducer and you should have the mentioned readings.

Worked with my 28V system, I checked the parts catalogue and IMHO the same transducer was installed in the 14V systems, too, so it should work.

Use a external power source, I am not quite sure but think the readings change with the bus voltage.

[Piloto]

Quote: FlyDave

Jose,

Thanks for the response.

Attached is a picture that was taken about a month ago. This is where the fuel pressure has been for the last 14 months that I've owned the plane. It seems something has changed.

When you experienced the higher fuel pressure before and after a rebuild, did it go up from a "normal" position or was it always high?

Thanks,

[Magnum]

Quote: Piloto

 Fuel pressure has always been high. Same with the oil pressure but not as high. These cluster gauges use a voltage regulator that at times vary. On my next annual I will look into it.

José

 

[FlyDave]

This past weekend the fuel pressure was pegged at the top of the gauge. My mechanic and I did an annual today and it turns out one of the connnections to the fuel pressure transducer was not good and came completely off in his hand when he went to inspect it. He re-did the electrical connections and fuel pressure indicates middle of the green and steady now.

It was nice to do an annual in 1 day -  removed the belly skins and inspection panels last night and re-installed them tonight. I'm flying tomorrow evening.