6.9 losing its prime

[terryknight]

I have a 6.9 in 350 dump truck. It's a great truck starts right up first time everytime unless you let it sit for a week or so and then it loses its prime. After sitting for a week I can unscrew the fuel filter top it off and it will start right up or I can sit there and crank and crank and eventually it will start. My question is why? Any help would be great.

I have replaced the fuel pump because someone told there was a check valve in it that may have gone bad, but it didn't solve the problem. Thanks

[03-blue-Powerstroke]

Heres a

[joedaddy_43]

I put on check vaule in mine half way between the tank and the filter. After that i never had any problems. I don't know if it solved the problem but i can tell you that it fires up all the time because there's fuel in the line all the time.

[kelmaur]

Originally Posted by terryknight

I have a 6.9 in 350 dump truck. It's a great truck starts right up first time everytime unless you let it sit for a week or so and then it loses its prime. After sitting for a week I can unscrew the fuel filter top it off and it will start right up or I can sit there and crank and crank and eventually it will start. My question is why? Any help would be great.

I have replaced the fuel pump because someone told there was a check valve in it that may have gone bad, but it didn't solve the problem. Thanks

tried seeing if there is air in the fuel lines and bleeding the line if so..

[kelmaur]

i have always had good luck with trying the simple stuff first and 90% of the time thats what it is