I have a holley red electric fuel pump that keeps blowing the 7.5 amp fuse. The pump is wired (soldered and heat shrink no shorts) with 12 gauge wire. Its mounted below the tank in a slightly angled but upright position. i had been noticing a hissing when I remove the gas cap. Also, the other night I filled up the tank and it blew the fuse twice within about 10 miles. I ran out of 7.5 amp fuses and used a 10 amp fuse from the radio. Then about 2 miles later the engine died (no fuel) but the fuse did not blow. I let the car sit for a minute or 2 and then it fired up. It did this once more without blowing the fuse and then ran fine for the next 30 miles or so. It seems like once the fuel level dropped in the tank the problem went away?

These pumps push fuel right? not pull?

My car used to have a LG4 with CC carb. Does it have an in tank helper pump? Could the sock in the tank be clogged causing the problem. I have a inline filter (in a glass sight) before the carb and it is clean. Whats the deal???

I can see that sometimes the sight glass where the filter is does not fill up like it normally did.

BTW- this setup ran great for about 1000 miles with no problems

 

It may have the "Vapor lock" preventing in-tank pump, and it could be dead. Your Holley pump must have been working hard to keep the engine supplied with fuel, and it wore out after only 1k miles. Other than that, maybe the pump is just going bad?

 

yes they have a lift pump in the tank. if your blowing the stock fuse in the fuse box then the pump is bad or a short in the stock wire is there. I would run 10ga wire for the fuel pump your using as every 12" distance will drop amps/volts X amount.

if your using the stock wiring and fuse to run both pumps then you will blow the fuse more and could melt wires causing a short to ground. check your power wire at the pump for short to ground with an ohm meter.

 

I have no shorts. I think I may drop the tank and see about removing the in tank pump like the sticky shows. I may take the pump apart to see if there is something wrong with it.

 

My no fuel problem with my Holley Red pump was a pinched fuel hose on the intake side of the pump. It would run fine for a while and then suck closed (collapse) at a 90* bend.

 

An '86 did not have an in-tank electric pump from the factory. It could have been added as a dealer-installed vapor lock kit as bradley indicated, but it isn't likely.

How do you know you don't have a short?