M35a2 Fuel issue

Oh. To answer your questions quickly;
I connected my test fuel line to the bottom of the booster pump "fuel inlet" with all other lines hooked up as they should be. There are 2 ports facing 6 o clock position on the booster pump my test line Is on the one towards the front of the motor. That is the line that comes from the primary filter.

If you hooked up a temporary line to the booster pump inlet and it ran then your issue is the supply to it. You need to have pressure at the booster pump inlet from the intank pump. I would work my way back towards the tank. Pulling the booster pump is fairly difficult. The intank pumps are known to fail. Keep us posted.


Eddie

My two cents .you need the intank pump to prime the booster pump witch can not prime itself. You said it ran fine on a temp supply when you elevated it ,that’s because it primed the booster pump. Now the truck will run with failed intank pump if the system is primed and doesn’t loose it , but you need the in tank pump to get started. Keep us posted

Big Tom

Good morning Welder and Big Tom. Thanks for the heads up guys. So I was given incorrect information and I've been chasing a ghost this whole time. So that's it then. Yeah the in tank pump kicked the bucket and a few guys said it's not needed so I pulled it out of the tank and put the housing back on with just the hose hanging straight down in the tank. Ok so easy enough I'll just have to get a new pump. Will keep ya posted

The info you were given is partially correct. The truck can run without the intank pump as long as you dont introduce ANY air between the tank and the booster pump. I have used air pressure to prime the booster pump on roadside when the guy ran too low on fuel and the engine quit. The intank pump self bleeds the system so it’s important that it work. I usually listen for it when I first switch on my truck prior to hitting starter button.


Eddie

Wrenchstench92 said:

Oh. To answer your questions quickly;
I connected my test fuel line to the bottom of the booster pump "fuel inlet" with all other lines hooked up as they should be. There are 2 ports facing 6 o clock position on the booster pump my test line Is on the one towards the front of the motor. That is the line that comes from the primary filter.

Click to expand...

OK then. Yes your booster pump is fine then. Like the others said, replace the in-tank pump.