The Stovebolt Site Forums The Shop Area The HiPo Shop electric fuel pump for priming

i am thinking about putting an electric fuel pump in line to fill the carb bowl after extended non-use. the idea would be to use as a primer with a momentary switch in the cab to pump fuel up for ~30 seconds before turning over the engine. i did this on my boat, but that has a main fuel pump that was electric. questions:

1) anything wrong with this idea?
2) anyone done it?
3) will fuel pumps pass fuel when not energized - better yet, anyone have a p/n that they know does this? once running, i want the mechanical pump to take over.

thanks for comments/ideas/feedback

Seems to me you might as well just let the electric pump just keep running. It shouldn't interfere with the mechanical pump, the pressures won't be additive so they won't overpower your float valve.

Not sure why it was necessary on your boat? The main pump should come on with the ignition and pressurize the line on its own.

thanks for the quick reply. didn't consider just leaving it running...

i had a 4.3L V6 in that boat - it had an electric fuel pump because the balance shaft prevented the use of the mechanical fuel pump.. i did it because i had to crank & crank that thing to get it to start and sometimes the battery was low because the bilge pump had been running.. it often sat for weeks. There was an oil pressure safety on this too, so no fuel until oil pressure built up. When i made this "primer" mod (which was really easy) it would fire up right away. but - not here to talk 'bout my boat...

tomctomc;

Put two tees in the existing fuel supply line with a check valve between the tees.
Hook your e-pump input to the 1st tee (fuel tank side) and the e-pump output to the 2nd tee (engine side). Hit the e-pump to prime and shut it down when the engines starts. The check valve will eliminate any backflow issues.
For your application you will need a low "cracking pressure" check valve.
Good luck;

SimS

thanks Sims.

I put one in line on a friends old Buick that had a hard time starting after setting for a period of time. It works real good. I used a spring return toggle switch.

wrenchbender - how did you set the plumbing up?

I tapped into the fuel line back by the tank. The mech. pump pumps through it.

Thanks for the reply. Thats how i want to do it.. i have to find an e-pump that will pass fuel when unpowered... anyone know a source for one?