I have a mechanical fuel pump on my chevy 350. I am puling fuel through the stock in tank fuel pump. After running it and then shutting it off the fuel will not stay in the lines. It drains back to the tank and has to be pumped back to the motor every time. Does anybody have any solutions for this?

 

Your fuel pump is probably weak/worn.

 

but its a brand new pump

 

Do you have any pressure reliefs for the tank? I had the one on my old 88 clog up and it would cause it to run dry. I'd take off the fuel cap and there would be a ton of pressure. But, it would instantly work again...

If that's happening the vacuum left in the tank could cause the fuel to flow back.

 

I had/have that same problem with my old blazer, man that's a real pita. I tryied diferent fuel pumps, didn't worked , finally went with electric, now the problem is still there, but now just open the acc. switch, and wait a few seconds, then pump it a couple times and fire it up. salud

 

Thats how i finally solved my problem also. Its not too hard either

 

Check your connections on your fuel tank, if the fuel tank was ever dropped or worked on. Even Toyota technicians have hooked up the fuel tank connections the wrong way.

 

Yeah when i dropped my tank i found that one of the lines was kinked. Not good. fixed that and put in an electric pump. works good now