Okay guys i could really use your help

[onus]

Has anyone ever had a problem with dud mechanical fuel pumps.

Everything is good on my lines, and everything no leaks.

Fuel filter lights comes on so there is too much suction on the IP side post fuel filter and it starts the run rough.

Good news is the truck runs like a top otherwise and it will start even after this problem with a few cranks unlike before it wouldn't start at all.

I'm gonna try the old diesel can test and bypass the fuel tank. My hardlines do look a bit rusty i'm not sure if there is a pin hole leak somewhere. Who knows.

New mechanical fuel pump.

Whats is everyone's thoughts?

 

[Dsl_Dog_Treat]

Have you done a fuel flow test at the schrader valve yet?

How many miles on the fuel filter?

 

[rhkcommander]

If you have new fuel caps make sure they are really for Diesel use. If they are for gas the lift pump won't be able to properly pull fuel. I had that issue a while back when I bought locking caps. Bought Diesel ones but they were cheap crap.

If there is rubber fuel line before the lift pump it could have collapsed internally. Also smell your oil, could be the diaphragm inside the pump leaking.
Just throwing some ideas out there

 

[onus]

Thanks guys.

Fuel filter has 2 miles on it.

Fuel at the valve. It gets plenty of fuel at idle but once you drive it it starts to drain the fuel filter and will pull suction on the ip side.

I have gates barricade hose from the hard line to the pump.

I believe it works with diesel. I'll check.

Yup i checked it says diesel is fine.

 

[Exekiel69]

You have a fuel restriction or possibly Your lift pump is done.

 

[smolkin]

What condition is the short piece of rubber hose right before the lift pump in? I've seen two '90's with a too-short loop there that collapses under suction. If it's not that, then does it have this problem on both tanks? It could be your tank pickups or a bad selector. Try the tank and tank selector bypass (diesel can) test. If it's still acting up with the tanks bypassed, it could be a bad lift pump after all.

 

[onus]

Yeah thats my thought a restriction, bad pump , or my sender is really broke, or my hard lines have a hole in them somewhere. I did hear that someone had there sender break at the top. I do know the shower head is broken but, the fuel level is far above the tank level where that is ever a problem.

I'd test the back tank but it leaks so i have never used it since I've owned the truck. Maybe i can try it anyway and pump out the extra fuel with my hand transfer pump when I'm done.

I'll try the gas can test in front of the lift pump first and keep testing back from there.

The rubber hose looks good. I made a big loop with it as thats how it was setup as before. Is that correct?

 

[smolkin]

The rubber hose looks good. I made a big loop with it as thats how it was setup as before. Is that correct?

That's how they came from the factory, so yes, but I also like to use a piece of split-loom over that hose to help it keep its shape. If you just replaced it then you're OK there, and I'm leaning towards a tank/selector problem.

 

[dgr]

I love this place. How big should that loop be?

 

[smolkin]

I love this place. How big should that loop be?

IIRC length of hose was 14-16"...I remember initially buying a 12" piece and not liking how close it was to kinking.