Crazy Fuel Pumps

well im new to the 78 style surban. i just got one. now, it ran fine and then it stopped getting fuel to the carb. so i go to check out the fuel pump well turned out i have two. one electric holley and then the mechanical one by the engine. now i dont know if that is normal or odd? anybody else have this? i replace the fuel filters. NO luck. so i am almost 100% sure its the fuel pump . but which one? do i need both? should i replacec one see if it works then go ahead and get the other one? shit. anybody that has any info would be much apriciated

I would say that the electric holley is aftermarket

yeah someone probably put the holley in and it just bypasses the one on the block. ive heard of people doing that when the one on the block goes bad

just my opinion, but electric pumps are junk. Ive replaced 2 in 6 months inside my gas tank. I would rathur have the mechanical that runs off the crank. Too many things to go wrong on the electric pumps compared to the mechanical. Plus, its a cinch to replace a mechanical. I swear the whole reason they made the electric pumps(especially the ones in the tank) is so you have to take it to a mechanic. With a mechanical pump you know its bad when your not getting gas, electric pumps it could be relays, sending units or about 10 other things.

Being your electric is external from the tank it wouldnt be so bad to replace it if you wanted to.

You cant get high enough fuel pressure with a mechanicle pump for fuel injection....