Isn't the check valve there to stop fuel running back when the pump isn't running? If the epump wasn't being powered the pressure from the stock mechanical lift pump would push the check valve open and allow fuel to flow through the epump no?. The reason I'm asking this is that I would want both pumps in the event of a failure of one.
I meant a check valve after each pump, then have them Y-together. if the mech. pump is on then it can't force fuel to the electric, or if the electric is on and the mech. has failed it wont force fuel there.
Or you could just use valves
. have the fuel line from the tank Y-off to both pumps, valves before each pump, and then have them Y back together to the filter/engine. open the valve for the pump you want shut the valve for the other. My mech. never failed, I would honestly just upgrade to electric and carry a spare if your extra worried. mines only attached by two bolts and two hose clamps, would be easy to change that in 5 minutes even in pitch black
Not sure how well mine is working, it quited down and pumped the diesel up pretty fast, opened the shrader to help it out. the pressure out of the stock filter seems less than the lift pump though. Still comes pouring out either way. Maybe I should just run the water sep? My compression could be pretty low and causing the rough starts too IDK anymore. I was playing with changing my glowplug time, it starts every time with 15 sec. Less and it tries but fails so IDK if its still purging or if I need intense heat to make up for the low comp