Lift pump won't prime!

[SSage]

The new latest and greatest Cummins Chinese pump is hard to push on, but it won't suck fuel from the tank. I thought it would be a quick fix again, I've changed the lift pumps out before. But, I can't get it to suck fuel much at all, pump primed a little and now its just air.

I'm guessing it must be the fuel screen in the tank, I'm just dreading the job. I gotta get the truck to a better location and out of the yard where it died. At least I got it back home, it lost power just after leaving the house again. I had to restart it 5 times in two miles. After it set for a couple days it wouldn't start, just blew black smoke after repeated cranking. Pulled the fuel filter and it was half empty, filled it up and it barely coughs and then dies. Cracked the injector lines, no fuel. I can't get the new lift pump to fill the pre-strainer. Any advice? I'm sick of these manual lift pumps, but I don't want to spend the money on an Air-Dog. I have one of those on my 2003, its whining now. I guess that pump will need repair soon too.

 

[Seabee]

Sound like you may have an air leak in you supply line and it just can't pull the fuel properly.

 

[Cummins12V98]

If you have not done it remove the fuel heater portion put it back together. Mine melted and caused a a air leak.

 

[SSage]

I must have a broken supply line or the sending unit is sucking air / clogged. I've been loosing power for some time, I just figured it was the leaking lift pump again. But, I still can't get the new lift pump to prime. I've replaced all the rubber hoses firewall forward and deleted the fuel heater years ago when it melted. I guess I'm way overdue for a tank drop and clean out. The fuel lines under the bed are all original.

Can you use a 96/97 model fuel sending unit on a 95? I see Geno's has those, my fuel gauge has been acting up for years now. Anyone try it? I haven't found much in my searches. I see one thread about using a generic sending unit.

 

[DavidC]

You could always run a hose from the suction side of the pump to a jug of diesel to verify before dropping the tank.

 

[mwilson]

I don’t know what part of the country you are in, but if the truck has been exposed to road chemicals the metal tubes on top of the fuel module have pinholes in them. I’ve personally fixed two 2nd Gens with that very issue.
I bought new fuel sending units and installed draw straws which allow you to keep the existing fuel module...
Send me your Vin and I’ll get you a solid part number for the sending unit..

 

[Joe Mc]

but if the truck has been exposed to road chemicals the metal tubes on top of the fuel module have pinholes in them. I bought new fuel sending units and installed draw straws which allow you to keep the existing fuel module.

Same thing happened on mine (I live in Eastern PA) about 14 years back, did the draw straw and a Glacier Diesel Perf. used their (at the time) big line, Walbro pump & psi regulator, and filter kit. Set-up has worked flawlessly since. Only thing I neglected to get was the H2O filter/catch. Last few winters I had situations where a slug of ice restricted the pump inlet and 1 time it started up and died shortly after the most recent (3 weeks back) after running for 10 minutes and thereafter driving about 8 miles to the TPK as I came up to speed she started chugging/loosing power. Both times Diesel 911 got me going again. Note: H2O filter/catch kit arriving this Thurs....