Archived I'm down - air in VP44? Need help ASAP

[Royk]

Went to start truck a little while ago and it wouldn't start. Looks like the lift pump is dying. I knew it was on its way out, since my pressure has been slowly dropping over the last year. In the last few weeks the truck would hesitate on start-up after sitting a while. I noticed the FP slow to come up when this happened. Just replaced the fuel filter even though I new it was good - NG. When I bump the starter, the pump sounds raspy. Mostly it will only get the FP guage up to about 3 pounds, sometimes 8-10 (which is normal FP at this point). When I crank the engine it drops to 0. I'm thinking there must be a check valve in the system somewhere. If so, where? I thought the VP would still suck fuel for a while even with a dead LP. However, the tank is near empty, which makes it harder to suck fuel. I've noticed my FP jump almost 5 pounds when I fill the tank.



What it comes down to is: How do you start this truck once it has sucked air?



Roy

 

[Hammer]

Roy. .

Sent you a pm to call me. Maybe I can help... ..... Andy

 

[Bob Wagner]

get some more diesel in the tank, personally I would screw with it until you have a new lift pump.



you can crack a couple of fuel injecto lines up at the valve cover 19mm wrench

 

[klaybus]

You can do it a couple of ways as long as your LP is still pumping.

1st...

Bump the key so the LP runs..... I've done it up to 15-20 times with a dying LP before she fired... . After 10-12 bumps hold the peddle to the floor while cranking it over. Don't crank it over for longer then 7-8 seconds though or you will heat up your starter motor.

2nd...

You can crack loose a few injector lines & then bump the started to cycle the LP & that will also purge the injection pump. Once you get fuel out of the lines, re-tighten them before trying to start it. I've seen that done while swapping out injectors though I've never had to do it.

Once it fires hold it up at about 1200 rpm's for a minute or two & let it run all the air out of the system.



Let us know how it turns out.



Good luck,

Clay

 

[DieselMinded]

Sounds like the LP is not pumping anything and maybe your VP44 is going south so its not sucking any fuel.



What would happen if you started it up with the Fuel Filter cap off ??? Do you guys think this would show possibly the vp$$ sucking the fuel and Mt'ing the canister or maybe it could show the LP suppying fuel?? I dont know ?? I guess if fuel went squrting all over the place it would be safe to say your LP is working ... a bit messy but atleast you wouldnt waste your time replacing parts thats not bad >?

 

[Royk]

Oo. Oo. YES!!!! I'M ALIVE!!! Oo. Oo. ( At least for the moment )



Many thanks to Hammer (who helped me over the phone) and Clay.



I went and filled up all the gas cans I could scrounge up and dumped about 13-15 gallons in the tank. Bumped the starter about 10-15 times, getting FP over 5 psi only 2 or 3 times. Tried starting as per Clay's suggestion of holding pedal to floor for many seconds. No Go! On the last attempt, as I turned key back to off, the truck burped! Tried again for another 7-10 seconds and she reluctantly started!!!! Never had to crack any injector lines! Oo. FP guage said 8 psi at idle. Drove to fuel station, with cruise FP at 7. 5 psi, and topped it off. On the way home, idle was 9-9. 5, cruise was pegged at 7. 5, and the lowest pressure I could get was 5, WOT up a steep grade from a standing start.



My dinner has been getting cold waiting for me for several hours, so I'm gonna quit for the night and see if she starts tomorrow. Thanks to everyone for the quick advice. I LOVE this place, although I was hoping to never post in this forum! I'm not out of the woods yet, so stand by.



Roy