one is on a switch. in case my pump ever dies. but what happens if i flip the switch while its running and have both pumping? like i said i just have a T fitting to feed them and another T fitting after them that go to the filter and up to the engine.. ill take pics as soon as its light out but im jw on your guy's ideas theory's or whatever

 

Fuel pumps?

 

Chevy guys.

Why did you do this? For redundancy? You are talking about fuel pumps, right?

Honestly I have no idea what would happen, but the second pump is not going to expect 60 psi of fuel on the intake side. I wouldn't expect it to last long like that.

 

That would happen with series pumps(1 after the other in-line) but what the OP described was a parallel arrangement with 2 pumps side by side feeding the same line. If the feed line is big enough it could deliver twice the volume and I know the late model Lightning fuel delivery units are built this way so the idea has merrit.

 

You're right Paul, I totally misread the post.

 

just temporary, but i was going for the added volume (not that my truck needs it) but i ran both it seems now im having problems with not getting enough spark with both on it shutters when i give it full throttle ive been due for distributor cap and rotor, and some plugs and wires for a while now, i was also looking in to this new multi spark distribution ignition module from pertronix called the flamethrower III it has a built in adjustable rev limiter!
PerTronix D7500700 - PerTronix Ignitor III® Replacement Flame-Thrower Distributor Modules - Overview - SummitRacing.com

 

If you don't have a check valves in each line directly after each pump I think it might not work so well. Don't the lightning pumps have check valves built in?

 

i assumed these had them too because one time i went to change the fuel filter and the truck had been sitting for days so when i unplugged it i was expecting gas but not pressurized gas to spray in my eyes