bakdoor

Pulled the fuel filter and replaced it last evening. Today, the truck started, ran for 30 seconds, and died. Now, she refuses to start. So I pulled the new filter and put the old one back in, but still a no-go. I can hear the electric fuel pump behind the filter housing running (the transfer pump?) after starting attempts. I'm assuming it's lost the fuel prime or something. The starter is cranking fine and I even hooked up jumper cables to another running vehicle to keep voltage up. Any suggestions to get her fired up again?

TIA!

dozer12216

Loosen the banjo bolt at VP44 from filter. Put in bump run and let fuel leak from fitting. Once get solid fuel from fitting, will have to loosen three injector line fittings at head. Again crank for few seconds and fuel should spurt from fittings. Snug down fittings and should start running roughly but will clear within 5 seconds.

johnh

that sounds exactly like my truck when my first lp failed...lp would run but wouldn't pump....first, fill filter housing with fuel then loosen the banjo bolt on the injection pump and bump the starter.
if you don't get any fuel as that point plan on replacing it.... it may pick up the prime without bleeding injectors, mine did.... but bleeding injectors are not that hard.

progrower

The same thing happened to me after i changed the fuel filter. Tried to reprime the pump but never got anywere. Finally figured the lift pump was bad. Replaced with the airdog 100.

bakdoor

OK, thanks for all the replies so far everyone. Now, for a couple of questions:

-is the lift pump the same as the transfer pump, or are we talking about two different things?

-if the lift pump is bad, would I still be able to hear it running?

-is the lift pump the pump right behind the fuel filter housing? Is this the VP44 that everyone talks about, or is the VP44 in the tank, or what?

Sorry, I know these are newbie questions. I'm not opposed to taking things apart myself and fixing/replacing stuff, but I just need to know what I'm taking apart. Any further clarifications are most appreciated.

fahtb0y

if you can hear the hum when you first turn the key without cranking than the pump should be fine. Lift and transfer pump are the same thing. I bled my fuel filter once and the same thing happened. My wife suggested putting more fuel in the tank. Thought she was crazy and after farting around under the truck for a half hour gave in to her suggestion. A five gallon can of #2 later and we were good. Just had to turn it to run a few times to give the pump a chance to suck fuel.

triker888

is the lift pump the same as the transfer pump, or are we talking about two different things? The Same Thing

-if the lift pump is bad, would I still be able to hear it running? Yes, that would be possible if the motor was running but the pump isn't pumping

-is the lift pump the pump right behind the fuel filter housing? Yes Is this the VP44 that everyone talks about, or is the VP44 in the tank, or what?It is not the VP. The VP is located towards the front of the motor on the same side. It has those 6 tubes coming out the back that go to the head.
Try the starter bump when the banjo bolt is loose from any of the fittings to find out if the "lift" pump is putting fuel to the VP

johnh

"-if the lift pump is bad, would I still be able to hear it running?"
yes, in some cases. like what happened to mine.......the stock lift pump has a check ball on the suction side. if it fails, the pump will still run but will not pump fuel

bakdoor

You hit the nail on the head here: I loosened the banjo bolt (after realizing that I first loosened the return line, then I got it right with the supply line.) When I bumped the starter, the LP was humming, but nothing was leaking out from the banjo bolt area. So I'm guessing the LP has taken the proverbial dump.

So: how hard is it to replace the LP? Anyone done this at home? I was looking at it, I'm not sure how it's gonna come out of there without the entire fuel filter housing coming out first.

rich

the easiest and cheapest replacement i did was a holley blue it cost me about 200 and took about an 1.5 hrs to do. you dont need to use the pressure regulator that comes with it

nitrousn

Good prices at Pensacola diesel.

https://www.dieseltruckresource.com/...d.php?t=238211

PChouinard

You had better get a fuel pressure guage installed when you put in the new lift pump. Since you found this problem during a filter change, you have no idea how long that lift pump hasn't been working. The main job of that lift pump is to send more fuel to the injection pump(vp44) than it needs. The fuel that is not used by the vp44 is used to cool the vp44 and then sent back to the tank. Without the lift pump working, your vp44 has been "pulling" the fuel from the tank itself. The vp44 only pulls the amount of fuel that is required by the engine, therefore, no coolling is taking place. Heat is the killer for these vp44 pumps.
What you need to do now is plug in a code reader and see if you have any codes from that fuel pump.

johnh

i took mine off the engine and put it on the frame..
I'm using two campaign pumps, the second one is a backup.
if one fails, i reach under and remove the electrical plug and plug it into the other one

johnh

it's real easy if you remove the filter housing,which is a simple job also.........if i remember two bolts an that's it

bakdoor

Well, thanks everyone for their advice. As it turns out, I definitely had air in the injector lines. I loosened three of the injector lines, did the starter bump several times until fuel started leaking out of them, and buttoned them back down. It took several cranking cycles, but it finally fired up. I now have a CEL on, but that's probably either due to low battery voltage from so much cranking or low fuel pressure or something. I'm gonna let it charge up, go for a ride and leave it run, and then see if the CEL goes out.

BTW, I really like that 2 pump set-up, johnh. What brand/model# pump did you use, and did you just extend the wiring harness all the way down there from the stock LP's location? I still think my LP is giving less than optimal pressure, and I think your set-up is the easiest to work on than the stock LPs location. Let me know when you get a chance. Thanks.

And again, thanks to everyone who chimed in here. IT'S ALIVE!