Sid Lambert
Well Known Member
Are these the symptoms of vapor lock about to happen?
Yesterday my wife and I flew over to Bama to visit her folks. My carbed 320 sits on the ground in the sun for about 4 hours. We get in and the air temp is about 84. We taxi back, do a nice run-up and then blast off.
Climbing at 115 KTS and about 4500 MSL the low fuel pressure warning alarm comes on. The pressure is 1.8 PSI. I turn on the boost pump and it goes to 5.1 PSI. I turn the boost pump off and it goes back down to 1.8. I switch tanks and the pressure stays about 1.8 PSI. We level off at 7500 MSL and I notice the fuel flow was about 12 GPH, way too high for 7500 MSL and 2400 RPM. I stay there for a few minutes and the fuel pressure starts to rise back to the normal 5.6 PSI and flow goes down to 7.8 GPH.
The engine never stumbled and the rest of the flight was uneventful but rough as a cobb.
I just installed the engine monitor at the end of last summer so the airplane could have been doing this from day 1 but I never notice because I had no FF and just a FP gauge mounted down low and almost out of site before.
Should I wrap my fuel lines in heat reflecting foil or just chalk it up to warm fuel on a warm day, no harm no foul?
Yesterday my wife and I flew over to Bama to visit her folks. My carbed 320 sits on the ground in the sun for about 4 hours. We get in and the air temp is about 84. We taxi back, do a nice run-up and then blast off.
Climbing at 115 KTS and about 4500 MSL the low fuel pressure warning alarm comes on. The pressure is 1.8 PSI. I turn on the boost pump and it goes to 5.1 PSI. I turn the boost pump off and it goes back down to 1.8. I switch tanks and the pressure stays about 1.8 PSI. We level off at 7500 MSL and I notice the fuel flow was about 12 GPH, way too high for 7500 MSL and 2400 RPM. I stay there for a few minutes and the fuel pressure starts to rise back to the normal 5.6 PSI and flow goes down to 7.8 GPH.
The engine never stumbled and the rest of the flight was uneventful but rough as a cobb.
I just installed the engine monitor at the end of last summer so the airplane could have been doing this from day 1 but I never notice because I had no FF and just a FP gauge mounted down low and almost out of site before.
Should I wrap my fuel lines in heat reflecting foil or just chalk it up to warm fuel on a warm day, no harm no foul?