my motor runs like buttery silk so far. (that's good!)
I am currently coming out of the f-350 center tank (which has NO lift pump- only a float and sender)
up to the frame to a 150 micron screw-off strainer (quart sized can) then forward to 2-nd gen dodge-cummins piston
pump running off crankshaft. I have NO lift pump.
It primes easy enough by just operating the plunger on the mechanical pump. When it sits overnight though it takes about 3 attempts to get a start. It is about 10 feet from the engine to the tank.
One solution would be to put in a fairly big check valve on the suction line just above the tank. would want the valve to open
at as low a pressure as possible. My suction line is 3/8 copper(with 1/4 return).
Another way would be to use some kind of small centrifugal pump which has some internal clearance- but that it would make just enough positive pressure to gently push the fuel forward- but at the same time have enough clearance to bypass some
so it wouldn't be angry if it wasn't passing much fuel. Also if this pump failed it wouldn't represent much fluid resistance
to the mechanical pump sucking through it.
I suppose I could also do some kind of 12 volt electric solenoid valve which would close as soon as the key is shut off.
Could be wired in parallel with the engine's electric fuel shut off valve.
But if that fails- engine stops.
Note: I have not done a real leak check on the lines and strainer. I can take the line off at the tank and engine pump-
add a little air and do a soapy water test ????? I guess I SHOULD do that first before I decide there is a real problem.
do I need some kind of expensive lift pump ?
Tim