Nukeflyboy
Well Known Member
Safety concern with fuel pressure sender
Ran the Garmin SB test on my hot engine and like some others, fuel pressure spike was essentially non-exsistent. Went from 25 psi at shutdown up to 25.2 in a few seconds, then decayed slowly to 10.4 over 5 minutes. This configuration is not at risk. In my case, Airflow Performance Silver Hawk EX on a stock Van?s YIO-540 with a fuel system plumbed per the drawings, no parts substitutions.
However a couple reports have been that fuel pressure had pegged the indication at 50 psi, including a friend?s RV-14. This is the limit of the reading and the pressure rating of the sender. Where actual pressure went is unknown and we now know that it has gotten high enough to fail the sender in a couple cases. The fuel configuration that causes this must be very ?tight? with no internal leakage. The fuel gets hydraulically locked in, heats up following shutdown, and pressure builds until something gives.
Ran the Garmin SB test on my hot engine and like some others, fuel pressure spike was essentially non-exsistent. Went from 25 psi at shutdown up to 25.2 in a few seconds, then decayed slowly to 10.4 over 5 minutes. This configuration is not at risk. In my case, Airflow Performance Silver Hawk EX on a stock Van?s YIO-540 with a fuel system plumbed per the drawings, no parts substitutions.
However a couple reports have been that fuel pressure had pegged the indication at 50 psi, including a friend?s RV-14. This is the limit of the reading and the pressure rating of the sender. Where actual pressure went is unknown and we now know that it has gotten high enough to fail the sender in a couple cases. The fuel configuration that causes this must be very ?tight? with no internal leakage. The fuel gets hydraulically locked in, heats up following shutdown, and pressure builds until something gives.