Anyone have any insight on the mechanical fuel pump? I've added an electric fuel pump cuz I got tired of messing with the mechanical... Right now the electric is running through the mechanical and I want to bypass the mechanical pump... Do I have to remove the mechanical pump and put a blank on the hole or can I leave the mechanical on the vehicle and run a fuel line loop?

 

You can put the plate over the old mechanical hole or just let it sit there. I'm assuming you're talking about an older Mopar. You said you're tired of messing with the mechanical pump. I rarely remember those fuel pumps going bad.

 

It's an 84 Dodge d250 3/4 ton with 318.... Yeah I put a new mechanical one in about 5 years ago. the truck has not been driven off and on for those five years "my bad".... Anyway so when I decided to start driving it again I couldn't get fuel up to the carburetor so I thought it was the mechanical fuel pump so I bought electric one and put it on now I'm having problems with electric pump getting in gas up there so I've changed the filters and I'm hoping that's going to work but I read somewhere that if you have the electric fuel pump running through the mechanical it's really hard on electric pump and could burn it out sooner than it's life expectancy does that make any sense?

 

It makes sense that extra pressure is put on the electric pump going through the mechanical pump. The fact that both pumps had difficulty pumping fuel tells me either there's a clogged screen in the tank or a kink in the line. I also came across a cracked line that sucked air.

 

I would bypass the mechanical pump, in some cases it works to have an electric pump assist the mechanical pump but in a stock motor situation you only need one pump. I have seen where the non-functional mechanical pump can be a restriction itself also a failed mechanical pump can fill the crankcase with gas.