BruceMe
Well Known Member
This has only happened a small number of times, but I wanted to post here to see if anyone can help.
Setup: RV-4, IO-320 160hp, Bendix RS-4, all fuel lines fire-sleaved, 100LL only.
Condition: cruise flight, 7gph economy cruise, 1.5hrs cross country, 55F at altitude
Observation: The fuel pressure started to fluctuate in cruise, jumping from 25psi to 12psi with a frequency of about one cycle every two seconds. If I turn the pump on, it goes solid again at ~25psi. Turn it off, it started again after a few minutes. Switching tanks didn't change anything.
My engine-driven mechanical diaphragm pump is about 12 years old now... maybe it's getting weak or hairline crack?
Thoughts/opinions/similar experiences welcome.
Setup: RV-4, IO-320 160hp, Bendix RS-4, all fuel lines fire-sleaved, 100LL only.
Condition: cruise flight, 7gph economy cruise, 1.5hrs cross country, 55F at altitude
Observation: The fuel pressure started to fluctuate in cruise, jumping from 25psi to 12psi with a frequency of about one cycle every two seconds. If I turn the pump on, it goes solid again at ~25psi. Turn it off, it started again after a few minutes. Switching tanks didn't change anything.
My engine-driven mechanical diaphragm pump is about 12 years old now... maybe it's getting weak or hairline crack?
Thoughts/opinions/similar experiences welcome.