Engine/Transmission (1998.5 - 2002) LP not running

[nutter3]

Hey guys, I'm having some issues with my fuel pressure.

I have the stock lift pump moved to the frame with the Vulcan big line kit.

A couple weeks ago the truck would not start after sitting for 10 days. ( it was a 10°F day) I tried a bunch to get it started. It originally had about 11 psi on the fuel gauge. After alot of cranking on it it finally started, but then died right away. It would restart with a little effort several times, but always died. I finally gave up to get my family to our house 120 miles away. Gelled fuel?



Fast forward 2 weeks and I finally got to work on it again. It started up immediately with 12 psi that day, it was about 30°F this time. Drove the truck home. By the time I got home my fuel pressure had dropped to around 4 psi the last 50 miles. Not good.

Now I have a condition where the lift pump will not run sometimes. I have taken to bumping the starter just to make sure now. Sometimes it will not run at all. Other times it will run 20 seconds or so just like it should and build up to 10-13 psi. Will a bad (or dying) lift pump run sometimes and not others? I thought most bad lift pumps were pumps that would not build enough pressure and/or flow, but were still running. Could the ECM be on its way out and not running the lift pump every time?

I'm seriously thinking of getting a Fuel boss, MITUSA, or the new DTT pump. Any pro's/cons of one over the other?



thanks for any suggestions.

 

[Bob Cochran]

I had one of my 3 OEM pumps that went bad just stop working. The others started to loss pressure over time. There could be more reason but typically the pump is bad. I use the Air Dog and am very happy with it but there is sure a lot of there good pumps out there as well. You just cannot trust the OEM Carter pumps at all. Oh I also had installed the Vulcan big line kit and relocated the OEM pump it helped a lot but was not the final cure,

 

[nutter3]

Thanks Bob.

I just figured it would:

1. Run with no or low pressure

or

2. Not run at all.



I wouldnt think it would run sometimes with proper pressure and not run at all at other times.

 

[DFerverda]

It will run with the fuse pulled on the pump, not very good but it will.
Do you read your fp post filter? I would plug in the block heater and see if it will stay running after the block is heated.
I would guess the filter is waxed up and letting some fuel through, or the system is getting some air.
I went through 2 walbro pumps and 3-4 stock lp's.
The last time i put in a raptor pump from glacier diesel, it has been in for several months and i really like it, and it has a lifetime warranty... .
Good luck, hope this helps.

 

[blacksheepdiesel]

I highly recommend AirDog after 318,000 miles on mine with zero issues. Even though I have seen below 0 temps I would want a fuel heater of some kind if I lived in Alaska which the AirDog does not have. Some guys plumb the AirDog through the original fuel can and take advantage of the heater there although some psi is lost by doing so. PM for AirDog dealer contact.

Godspeed,
Trent

 

[jeepit]

I highly recommend AirDog after 318,000 miles on mine with zero issues. Even though I have seen below 0 temps I would want a fuel heater of some kind if I lived in Alaska which the AirDog does not have. Some guys plumb the AirDog through the original fuel can and take advantage of the heater there although some psi is lost by doing so. PM for AirDog dealer contact.



Godspeed,

Trent

I had my truck in -10 a couple of times. I always use anti gel additive in winter but never had a problem starting w/o fuel heater... .

 

[TimBrunett]

LP going bad

Hey Nutter3

I'm having the same issue with mine although not as cold here, just a weak LP. I've been watching my FP go down slowly for a while now and I know the end is near.
But I hate to spend the big bucks for a FASS just before Christmas. Kinda want to get by for the time being.

So do you or does anybody know where a stock LP for the best price?

Any suggestions would be very helpful.

Thanks

TB

 

[JR2]

Nutter

Check all your electrical connections. Do the Dielectric grease thing on all the connections that control the punp. Your problem really sounds like an intermitant ground type deal. Good luck and give me a shout on my cell if you need anything.

 

[nutter3]

I cleaned all the LP harnesses. Put in a new cummins lift pump and a new fuel filter. Hit the key a few times to get pressure. It started right up and then died. Hit the key again and no LP running. . So I hooked in my voltmeter to watch the voltage to the LP. This time it ran fine, engine started with no problems.

I think I'll be ordering a fuel boss and getting that put in. Until then, I'll watch the voltage to the LP

 

[JR2]

I think you need a new truck, that one is just not reliable any more...