Higher fuel pressure when cold OAT?

[Jcurry]

Hello,
My fuel press is going too high and triggering the alarm on my Dynon D180. This has been happening since we dropped into the 30s. I don't if this is temp related or if the fuel press xducer is failing on me. I suspect the latter. I'm sure I have the old school xducer. My xducer is mounted on the fire wall.
What do you think? Thanks.

[lr172]

quite unlikely that cold temps would make any meaningful difference in fluid pressure sensor readings. An exception would be a sensor that is failing inside, but only acting up / showing symptoms when cold. That is not uncommon. The old diaphragm style sensors (transducers are solid state) do not last forever and not uncommon to fail early. Sensors have only two connections (sometimes only one connector and grounded via the threads) and transducers have three (almost never grounded via threads).

[Cth6]

Originally Posted by Jcurry

Hello,
My fuel press is going too high and triggering the alarm on my Dynon D180. This has been happening since we dropped into the 30s. I don't if this is temp related or if the fuel press xducer is failing on me. I suspect the latter. I'm sure I have the old school xducer. My xducer is mounted on the fire wall.
What do you think? Thanks.

Once the engine is warmed up does the alarm go away? If not, I would surmise that the sender is warmed enough by the engine to point to a bad transducer.

[Avanza]

At +32F water may freeze.
Depending on where the xducer is located in the system this may
show up as high or low pressure.

Good luck

[Jcurry]

Originally Posted by lr172

quite unlikely that cold temps would make any meaningful difference in fluid pressure sensor readings. An exception would be a sensor that is failing inside, but only acting up / showing symptoms when cold. That is not uncommon. The old diaphragm style sensors (transducers are solid state) do not last forever and not uncommon to fail early. Sensors have only two connections (sometimes only one connector and grounded via the threads) and transducers have three (almost never grounded via threads).

Hi Larry,
I agree with everything you said. I was using the term transducer loosely. Thanks for your reply. I now have a fuel pressure sensor and oil pressure sensor on order.

[Jcurry]

Originally Posted by Cth6

Once the engine is warmed up does the alarm go away? If not, I would surmise that the sender is warmed enough by the engine to point to a bad transducer.

Hi CT,
Thanks for your reply. I also believe the sensor is failing.

[IlliniRV12]

I too had a high fuel pressure alert on my Dynon D180 yesterday in cold weather 24 degrees. If you replaced the fuel pressure sensor and oil pressure sensor did it fix the problem and where did you purchase them from?

Jerry Kewanee Illinois

[tfoster100]

I also noticed high fuel pressure readings in the cold weather here in Dallas. Wasn’t that cold around 30’s. Newer build with only 45 hours. May look into replacing as well.

[Jcurry]

Originally Posted by IlliniRV12

I too had a high fuel pressure alert on my Dynon D180 yesterday in cold weather 24 degrees. If you replaced the fuel pressure sensor and oil pressure sensor did it fix the problem and where did you purchase them from?

Jerry Kewanee Illinois

Hi Jerry,
I'm "winging" this but in conjunction with what Larry said above, I suspect the diaphragm in older sensors are less pliable and stiffen considerably in colder temps producing higher readings. That's my theory...
My parts have not arrived yet. They are due in tomorrow. I ordered the sensors on Amazon.
Fuel Sensor 360-043 0-30 psi $58.16
Oil Sensor 360-430 0-150 psi $71.42

Of course it's warming back up here in Florida....

[IlliniRV12]

Hello Jack

It's 54 degress in Illinois right now all the snow has melted. Thank you for quick your response. My annual is coming up next month so I will have plenty to do, thank you for the part numbers. Jerry