Engine/Transmission (1998.5 - 2002) Major Problem...Need Some Help

[Bigstick]

Lift pump went out last week so I went to Cummins bought new one and put on myself. Truck has ran great for a week, then the other day I had to crank for a second or two longer to get her started. It has done this to me a couple times, seems like it is losing its prime. Then the other night she stumbled and cut out a few times when I was accelerating. A time or two it got to 2200-2500 and wouldn't go no higher. THen yesterday I went to a festival and when I came out, I cranked for about 5 minutes of of and on cranking, finally held my foot on the floor and cranked for about 25 seconds straight and it started. Then twice last night after sitting for 15 mintues it did the same thing and when I cracked my #1 injector line at the block I had air. On the way home the I was driving normal and any hill I went up or and load that was put on the motor made the truck start stumbling and cutting out. I was driving normal holding steady rpm and every hill I went up made the truck do this. When I got home I shut it off and immediately tried to start it back up and nothing just cranking. I have checked all fuel lines around lift pump block and injection pump and they all are tight no leaks. I am so frustrated I do not know waht to do. I need some help and assistance please. I have Edge Drag Comp, Anti De-Fueling Device, Injectors, and a few other things. THanks in advance.

 

[Shovelhead]

When you changed the lift pump, did you also install new washers on the banjo bolts?

Could be a slight tear on one of the washer's seals allowing air into the fuel system.

What is you fuel pressure after the change?

 

[Ramafid]

I know you said everything is tight but it sure sounds like there is air in the fuel system. I guess another problem could be that the injection pump is going bad. Hope you get it fixed soon.

 

[Ncostello]

I'm not sure without doing some looking, but I thought that I read somewhere that quite a few lift pumps are bad right off the shelf. I'd say is getting air in somewhere in a very small amount. Thats what they do with a little air. Cut out, stumble etc.



Its a sinking feeling when these things get air (true with any diesel) in the system. Cause when it starts to shut down with air in the lines, there is nothing you can do to stop it. At least it didn't leave you stranded.



I'd be checking that pressure.

 

[wyosteve]

Hope I'm not the bearer of bad news, but it sounds just like what happened when my VP-44 died.

 

[Wiredawg]

Could be air leak in front of pump

I would suspect a leak in a fitting in front of the pump. Because the pump pulls (sucks, no pun intended) you may not see fuel dripping. Check the fittings into the pump and the banjo fittings tightness. Be careful not to over tighten as the banjo fittings can distort, causing more problems.



If you still have problems after checking tightness, I would change banjo fitting washers.



Good luck and let us know what you find.



Wiredawg

 

[Bigstick]

Fuel pressure is 10-13 psi at idle and crusing down the road. When the lift pump runs for 25 seconds it is 10-15 psi that is at the back of the filter housing. I have been making myself sick when I think of the VP44 but I have been told that when these things go bad, they don't show any signs, the just drop off all at once. I dunno, I am just sick.

 

[RADdodge]

Fuel Filter?

It might not hurt to try changing the fuel filter.

 

[Bigstick]

Okay changed fuel filter, checked all wire connections and used dielectric grease, truck started almost normal when cold. Ran it up the road warmed it up, no misses, got home checked fuel pressure while running. At the filter I had 12-14 psi, at the injection pump it was 14 psi and 12 psi at 2500 rpm. Shut it off would no restart. Let the lifter pump run its 25 second cycle, at the injection pump it squirted air bubbles and then had 15 psi at injection pump and at the filter. Opened the #1 line at the block and it took cranking for about 10-15 seconds to get solid fuel at that line. I don't know if this is normal but, the pressure dropped right back to 0 at both locations as soon as the lift pump kicked off I thought it would hold pressure. The return valve/pressure release vavle at the injection pump works properly. Now I am going back to the service manuals again for more research. I still do not think it is the injection pump. There is definately a fuel supply problem still no leaks. How could I check the lifter pump to make sure it is working properly, I know it has good pressure but I dunno if it is letting air in or losing prime. ARGH!!!!!

 

[Bigstick]

I also saw somewhere but now lost it where you could power and ground the #6 and #7 pin on the injection pump to see if it was good or bad. Need more info on that, the last thing I want to do is vist the dealer.

 

[Big White Beast]

I suppose.........

You could hook a hose to the output and flow it into a container. That would show youyr fuel flow amount. Put a small valve on the end of the hose and slowly build pressure against the lift pump and see what it does.



One I tested read zero PSI untill the VP suck started it. Then it would jump up to normal pressure. I would take it back to Cummins and try a new one. You never had the problem before replacing so that tells you something.



Garrett

 

[andrewkoperdak]

Bigstick,



Sure sounds like an air leak somewhere. I know you said everything is sound. I did to when I complained about my fuel pres gauge getting air in it. I tightened all my fittings again and I have had not one problem since.

To test the Xfer pump, you could slip off the rubber hose fromt he pump to the filter housing and let it go into a coke bottle or something for the 25 seconds of run. Better make it a 20 oz bottle as the quantity might exceede the standard 12 oz can.

Hope you find the problem.

Andy

 

[Carle]

I have not seen it mentioned anywhere so I thought I would reply to this. Banjo bolts and washers should be torqued to 18 ft lbs. This is very important as the washers are very easily crushed which will cause numerous problems, including the one described. The banjo bolt washers at the pump are very easily damaged or even lost if you are not careful.



Carle

 

[Bigstick]

Tonight I got another lift pump from Cummins for free under warranty of the last one I purchased, and I also got new banjo washers and a return valve(they said they always replace with the lfit pump). I finally got the truck running after bleeding the injector lines for about 30-45 minutes. Let her idle for about 20 minutes then drove around. This is what really confuses me, the truck ran better than ever tonight no misses spits or sputters. With the box on all levels, and with the box off the thing ran great. I got home shut it off and went to restart... ... nothing just a lot of cranking, so it seems that I have great pressures (14 psi) at the injection pump but when shut off the fuel loses it 's prime at the block. I am really lost now about to go back to cummins and let them hook up the computer. THen maybe regretfully take it to dodge. Thanks in advance for everyone's help.

 

[Steve Campbell]

Could it be possible...

that the outlet Banjo on the VP44 is malfunctioning?



How about fuel pressure during cranking? Steve ST. said with his aftermarket set up, he has too much pressure and has to wait for the lift pump cycle to end before cranking. Too much pressure "floods" the VP44 during cranking. It is suppose to be about 5 psi.

 

[Sean Flanagan]

My 98. 5 had a similar problem. It turned out to be a crack in the fuel return line coming out of the Injector pump. The only difference is that the leak was obvious from the little puddle of fuel it left on the driveway.

 

[Bigstick]

New Problem

Okay after talking to several very intelligent Cummins mechanics around the local truck garages here, we have verified the problem and the cause. THe problem is that the VP-44 is shot/going bad. The cause was nothing to do with the performance upgrades that I have done. The cause was when the lift pump went out, the injection pump sucked air and ruined some seals on the inside. This is letting the pressure drop when the truck is shut off. I have now put my truck back to stock form except tires and lift and am making an appointment at the dealer. ANy suggestions for clearing codes or covering up spliced fuel pump wires?

 

[Big White Beast]

That's gotta hurt.......

One more reason to make sure the lift pumps are monitored and maintained for adequate pressure.



How long was your original lift pump out? Or was it Cummins replacement pump that let the air in the line? It seems your problem started after the new pump was on for a week or so. Maybe you could hold Cummins responsible if the dealer doesn't come through. They admit it had nothing to do with your mods.



Just a thought,



Garrett

 

[Whiskey]

WONDER IF YOU HAVE TRIED TO LOOSEN THE FUEL CAP????

 

[Bigstick]

My stock pump went out and I drove about 1/4 mile to dad's shop and dropped it there and went to buy a new one from Cummins at 10:00 pm. THey said as soon as the lift pump went out it only takes up to 5 minutes to suck in air to do damage and that you may not see signs of bad injection pump for a while depends on how much fuel you are trying to move through it. In my case that is a lot of fuel. I have tried the fuel cap. I returned the truck to a dealership today in stock form.