jjconstant
Well Known Member
Hi all
I'm in the latter stages of Phase 1 and every now and then I get a high fuel pressure reading, using just the mechanical fuel pump. Sometimes on the ground right after starting, sometimes in the runup area, sometimes in flight.
I have the standard Van's vertical fuel injection and I set my high fuel pressure alarms at 36 psi. My normal indications are 27 to 31 psi. The first few times, I taxied back to the hangar, decowled, futzed around with the sender wires, opened the fitting to vent to atmosphere, etc.
My understanding is that the diaphragm in the mechanical fuel pump is only capable of either generating the appropriate fuel pressure or rupturing and generating LOW pressure, not high. Is that a reasonably accurate understanding?
What are some things that could generate actually HIGH fuel pressure with the mech pump only? Cloged or blocked lines/injectors upstream of the pump?
Or, is a high fuel pressure alarm actually a) useful and b) telling me anything other than my sender is unreliable?
Thanks for your time
Jeremy
RV7A Phase 1
I'm in the latter stages of Phase 1 and every now and then I get a high fuel pressure reading, using just the mechanical fuel pump. Sometimes on the ground right after starting, sometimes in the runup area, sometimes in flight.
I have the standard Van's vertical fuel injection and I set my high fuel pressure alarms at 36 psi. My normal indications are 27 to 31 psi. The first few times, I taxied back to the hangar, decowled, futzed around with the sender wires, opened the fitting to vent to atmosphere, etc.
My understanding is that the diaphragm in the mechanical fuel pump is only capable of either generating the appropriate fuel pressure or rupturing and generating LOW pressure, not high. Is that a reasonably accurate understanding?
What are some things that could generate actually HIGH fuel pressure with the mech pump only? Cloged or blocked lines/injectors upstream of the pump?
Or, is a high fuel pressure alarm actually a) useful and b) telling me anything other than my sender is unreliable?
Thanks for your time
Jeremy
RV7A Phase 1