[SquawkVFR]

After reviewing the Lycoming IO-360 manual, I found that my indicated fuel pressure is out of spec with Lycoming's Operating Instructions. My fuel pressure sender is tapped off the output end of the mechanical fuel pump, which means it needs to be between 14 and 45 psi. My EMS typically indicates the pressure hovers around 9.5 psi most of the time. The sender is an old VDO 0 - 5 bar unit.

Engine runs fine and makes plenty of power, so I suspect the sender is not reporting correctly and/or EMS is not configured properly. I just bought this airplane and haven't tried to mess with the settings yet. I visually inspected the sender terminal, and it appears to be free of any egregious corrosion. I may disconnect it and sand down the contact points a tiny bit to see if that helps.

I've searched the web and this forum and haven't found anyone offer concrete fuel pressure requirements, but there are limits provided in Lycoming's manual to which I'd like to adhere. This screenshot was taken from Page 3-10. What are your thoughts? Should I try another VDO, check the EMS settings, try a different type of sender, sell the airplane? All comments welcome.

 

[DanH]

Ali, you have the correct numbers. Most like to see 25 to 30 psi as the "normal" range.

The VDO senders are not super reliable. Can't speak to EIS configuration; don't know what you have.

 

[VA Maule]

Considering you report it running well, I’d suspect that the electric sender is probably not reading/reporting correctly. I’d “T” in a old school manual direct reading gage temporarily secured in such a way that you or a helper can observe it during a run up check and compare the readings.