thunder669
Active Member
So I have had an intermittent issue that has raised the blood pressure. Twice I had the engine start sputtering in a climb at high power settings when i was at about a half tank in the left tank. I Immediately switch tanks and turn on electric pump and engine started running perfect again. natural assumption was that I had a fuel pickup problem. I eliminated this theory by disconnecting fuel line at carb and turning on electric pump. left tank pumped completely empty. so I next thought maybe a plugged vent line causing a bit of vapor lock and blew through the vent line to ensure it was clear. Then yesterday morning we flew to get breakfast and top the plane off at a nearby airport with cheaper fuel. shortly after takeoff a couple miles north of the field the engine started to sputter. but this time I had a full tank and was on the right tank. once again switching tanks and kicking on boost pump returned the engine to normal. After circling for a couple minutes I switched back to the right tank and plane continued to run normal. This was after I had leveled off and reduced power.
This leaves me thinking the mechanical pump is starting to fail since it has now happened on both tanks and kicking on the boost pump fixes the issue. the only other theory I have is I replaced the factory vents with the streamlined ones from JDair. Are these somehow not allowing enough air to flow when at max power in a climb attitude causing a type of vapor lock that the boost pump is able to overcome?
This is in my new to me RV4 with an O360. My wife loved flying in our Comanche and needless to say this has her a bit spooked about flying in the 4 so I need to make sure it is corrected and quick. Open to any other Ideas you guys might have
This leaves me thinking the mechanical pump is starting to fail since it has now happened on both tanks and kicking on the boost pump fixes the issue. the only other theory I have is I replaced the factory vents with the streamlined ones from JDair. Are these somehow not allowing enough air to flow when at max power in a climb attitude causing a type of vapor lock that the boost pump is able to overcome?
This is in my new to me RV4 with an O360. My wife loved flying in our Comanche and needless to say this has her a bit spooked about flying in the 4 so I need to make sure it is corrected and quick. Open to any other Ideas you guys might have