This is on my Dad's 1999 24 valve. Let me start from the beginning. A few weeks ago he started having problems with it not wanting to start. He talked with a few different people and was told different things. One said it was the crankshaft sensor and another said it was the injector pump (even though it was showing no codes on the computer). A third told him to run some Lucas fuel conditioner thru it and it would fix the problem. Since this was the easiest and least expensive, he tried the Lucas first. And it began to start OK.

Well, today I changed the fuel filter on it like I have on his and mine several times. After reconnecting everything, it started right up, but then died. So, thinking it must have some air in the line, I loosened the bleeder plug on top of the canister and bumped the starter to get the lift pump to operate. I can hear the lift pump but no fuel is being pumped to the filter canister.

One more detail. Before changing the fuel filter I connected a fuel pressure gauge to the top of the filter canister (post-filter) and it would not register any pressure. Since I hadn't used the gauge in a while I thought it must not be working. Well, after changing his filter and not being able to start the engine, I connected the pressure gauge to my truck and it works.

Here are my questions:

1) Am I correct in thinking that his lift pump is shot?

2) If the pressure gauge showed no pressure, how was the truck able to start?

3) Could there have been enough prime in the fuel line that the injector pump was able to pull the fuel to run the engine, and when I changed the filter it lost the prime?

4) Why did the Lucas fuel treatment fix the hard starting problem?

5) Am I also correct in thinking that, with the lift pump being weak, it was just a matter of time until he would be having injector pump problems?

It's been a while since I've been on here, but I knew this is the first place I needed to go to get some good help with this problem. Thanks in advance for any help and info that you can give me.

Charlie

 

1- Yes, that is a safe bet.

2- There was enough fuel in the lines for it to start and run, the injection pump can supply enough fuel for the truck to run, but not the excess needed to lube and cool the VP44.

3- Exactly

4- Most likely a coincedence. The Lucas could have cleaned out any gunk that might have been blocking things, even leading to the failure of the lift pump.

5- Again, a safe bet. It would be a good idea to start saving.
Or, it could last a long time, but not likely.


phox

 

Either you have a restriction in the fuel system or the lift pump is gone. Most likely the lift pump is shot. The reason the truck started is that there was no air in the system and the VP 44 is actually capable of pulling a small amount of fuel. I've checked the psi on some and actually had a negative reading because the VP was doing all the work. This is the reason as to why in most cases when the injection pump fails a new lift pump is also installed. If you absolutely need the truck started you can pressurize the fuel tank with a little compressed air and continue bleeding the system. I've done this so I could at least pull the truck outside. If you want to verify the fuel delivery system is ok you can put a hose on the lift pump inlet and run the other end to a fuel jug with diesel in it and check the pump volume. If you separate the line from the filter to the vp44 (rubber connecting point) you can bump the starter and the lift pump should run for 25 seconds. If you do not get more than 1.3 liters of fuel in that time you need a lift pump.

 

6: Under NO circumstances pay the $300 that the Dodge dealer wants for a replacement Lift pump.

If it's not covered by the 100,000 mile warranty, pick one up at your closest Cummins parts distributor.
(on the '99, you'll probably need the wiring pigtail also.)
It also might be a good idea to pick up 4 new sealing washers while you're there.

Ed

 

I knew that I would get some good help! I'll be checking with the Cummins distributor in Tulsa tomorrow.

Thanks for the info and it's good to get back on here and talk with you all again.

Charlie

 

$165 for lift pump, wiring pigtail adapter, and sealing washers from South Plains Cummins in Tulsa.

CR

 

 

Installed new lift pump last night and truck is starting great now. Apparently, this is not the first time the lift pump has been changed on this truck ( it had 125K on it when my dad bought it ), as there were no sealing washers between the banjo bolts and the lift pump.

Now I'm wondering if this could have been part of the problem and maybe the old pump is not totally shot after all. Because you could hear the old pump working when you bumped the starter, but there was no fuel being pumped. Anyone ever take an old pump apart and clean the screens and get it working again? Just wondering if maybe I could use it for a backup in case I needed another pump sometime.

CR

 

Just because you hear the motor running doesn't mean the pump is actually moving fuel. The coupling between the motor & pump may be shot, or the relief valve in the pump may not be seating.

Rusty

 

Is it possible to quote yourself?

Anyway, bad news. Dad started truck this morning OK and drove about 70 miles to where he was working. When he finished working the truck was hard to start, but he did get it started and drove the 70 miles back home. Once he got home and killed the engine it won't start now. Looks like the lift pump going bad may have also taken out the injector pump. My question is this.....can we pull the truck to start it and, if so, will it hurt anything to drive it like this so we can take the truck about 20 miles to where we can get the codes checked to make sure it is the injector pump?

CR

 

pulling the truck isn't going to get it started. Personnally I would tow it in.

 

I'd have to agree with J Body.
I'd call for a tow truck.

 

OK, here's the latest. Yesterday evening I checked the fuel pressure (post filter) and it was OK. So I cracked the first injector line and cranked the engine and it started. Let it run for a bit and killed it. Wouldn't start. Cracked first injector line. Won't start. Cracked first and third injector lines. Won't start. So, it must be bad VP44.

Now, my dad just called me at work and, just for kicks, he cranked the engine this morning and it starts. In fact, he has started it three times. Kicks right off.

What are we missing here? I've heard mention of the cam sensor and the crank sensor. Could one of these be causing the problem, maybe? We're open to all suggestions, hoping that maybe we won't have to change the VP44 after all.

CR

 

make sure you dont have bad lines from the tank to the lift pump.
leaking lines are pretty common .