fuel pump priming issue

[longhornfan1960]

I have an 82 CJ5 with a 6 banger and mechanical fuel pump. When it sits for a few days the pump won't pick up the fuel so I have to prime it by blowing air into the gas tank. Once primed, the pump works fine. It seems the fuel is running back to the tank, leaving the fuel pump dry. Any ideas what causes this and how to stop it?

 

[Jet]

I had the same problem when i 1st. got my 84.
I replaced all the rubber fuel hoses from the carb. to the tank.
I didn't want to drop the tank, so i couldn't reach far enough to get them all. But it works.

 

[gillmore]

Check your fuel filter too. If it has 2 outlets, the one going to the carb should be below the one that returns to the tank. This and replacing my rubber fuel lines helped me a lot.

 

[ThisGuyUKnow]

'lectric fuel pump! totally worth it. Did it to my wag and have been very impressed with the results.

 

[jeffgtoman]

You might need a new fuel pump. It has little rubber flaps in it that act as a check valve. If it is old and the flaps are warped, it could cause your problem.

 

[longhornfan1960]

I've ordered new pump and gas cap and have put in some new rubber lines. Maybe one of these will stop the backflow. Putting in an electric fuel pump has been suggested but that type of real mechanic work is way above my pay grade.

 

[CJ]

Air is getting into the fuel line - could be a pin hole leak in the rubber lines, the fuel pump flaps, the needle valve in the carb, or even a rusted pickup tube.

As stated, try the rubber lines first. If you have a vacuum pump, you can pump down the line from the pickup at the tank and see if it leaks down. If not, work your way up to the carb to find the leak.

Droid!

 

[ThisGuyUKnow]

I've ordered new pump and gas cap and have put in some new rubber lines. Maybe one of these will stop the backflow. Putting in an electric fuel pump has been suggested but that type of real mechanic work is way above my pay grade.

The electric pump is super easy to install I think u would be surprised what u can do.