I am relatively new to the diesel world and have a few questions about my fuel system. I have a 1998.5 (24 Valve) Dodge 2500 Cummins, which I purchased a few months ago. I have been driving the truck daily and making 300 mile round trip drives every weekend for the past 4 months. This past weekend, I went to start the truck, but it would only turn over; it wouldn't fire. It was running fine when I parked it, just 10 hours before, and just like someone turned off a switch, it won't fire at all now. Has anyone ever heard of this happening before?

I began troubleshooting, using my Haynes manual, but I am a little confused on the terminology of the components. I have heard many people refer to a "lift pump" and Haynes refers to a "transfer pump". Is this the same pump?

 

Check for blown fuse. I can't remember from my 98 what would be in the fuse box......like ECM, Fuel pump.......check'm all.

 

It is common for the lift pump( transfer) to fail. There is a schrader vavle on the injection pump to test pressure. You can also loosen the filter ( you need to change it) and bump the starter. The lift pump should runabout 25 seconds then shut off. It may run but not create pressure.
The second thing to check is fuel at the injectors. simply loosen two injectors at the head, crank the motor over, go look for fuel leaks at those lines.
It also could be a failed injection pump-vp44- which will cost from $1000 to $3000 depending on whether you do it your self or hire some to change it.

 

I believe the lift pump and the transfer pump are the same thing (just depends on who your talking to) Is your truck throwing any codes? FYI if you get a pen and paper and look where the odometer is then put the key in the ignition (don't actually start truck) turn key to on then off position 3 times if it throws any codes they will show up as letters and numbers where the odometer is......the codes go pretty fast you might have to do it more than once. I would say off hand it is the lift pump and/or the VP44 (injection pump) '98-'02's had A LOT of problems with them both........I had to replace both in my '02 a year and half ago. Hope I'm REALLY wrong!!! It's a pain to work on!!! Take care and let us know either way.

 

I have already replaced the filter with a new one. When I dropped the canister, there was only about 3/4 - 1 inch of fuel in the bottom. Should this be full? Anyway, I can hear the pump run for 25 seconds. Also, I followed the procedure in the owners manual and "bumped" the starter to cause the pump to run for 25 seconds a total of 4 times, then opened the water drain on the filter to check for fuel, but have nothing. The tank is just under 1/2, so I know it has plenty of fuel. Also, before I changed the filter, I could open the water drain and fuel would flow out. Is there any other pump between the tank and this one? Do I need to prime the line between the pump and the tank following the filter change?

 

Thanks DIEZELCHICK!

I'll check for codes tonight after work.

 

Please fill out your sig so we know a bit more about your truck.

You won't be able to get the codes with the key trick on a 98.5, you will have to get a scanner from the auto parts stores. Most will rent them or loan them. You will need the codes however.

If you don't have any fuel in the canister by now the lift pump has failed. They will run and not pump fuel. The really best way to insure the filter housing is full is to hook up a hose to the front fitting on the top of the housing and run it into a clean gallon jug. In 25 sec you should get a sizble amount of fuel out. If not replace the lift pump.

You absolutely need a fuel pressure gage on the 2nd gen trucks. It measures the health of your fuel system. That said even a made up hose and mechanical gage from the parts store is usable. Pressure is pressure so any gage that reads 15 psi up to about 30 is ok. You need to see 14 psi at idle and cruise.

To bleed the air out of the system you need to crack or loosen injector lines 1,2 nd 4 and crank the motor. A sizable amount of high pressure fuel should come out. Only crank the motor about 30 sec then wait a couple minutes and try again. Usually 2-3 times is all it takes. The motor should start if every thing is ok. Stop and tighten the lines or there will be fuel all over. The motor will run rough for a couple minutes then smooth out.

No start you will need codes now. So get this far then post again.

 

There are a couple of things to watch for on the 98.5 24 valve Cummins engined Dodge.

The most common fuel supply failure is the lift pump, which is the transfer pump. The best way to check it is to have someone bump the starter without starting, to cycle the pump while you open the bleed valve on the filter. If the pump runs but does not output fuel you have a pump bypass valve stuck and the pump needs to be replaced. If the pump does not run, then check the electrical supply to be sure you have not blown a fuse, and if there is power to the pump then the pump is burned out and needs replaced.

If the pump runs and sucks air and spits lots of bubbles and little fuel, then you need to replace the soft fuel lines. There are a bunch of them, two to the engine, and two down on top of the tank. Use diesel rated lines.

If the pump runs and blows air and no fuel, then you have a failure in the pick-up tube in the tank. Common problem after the trucks get some age on them. Drop the tank or lift the bed and pull the assembly from the tank and install a new pick-up hose and tank end. Or get on of the improved aftermarket units from one of the site sponsors.

Worst case your injection pump may be toast. Also a common problem with the 24 valve engines if they are allowed to run with dirty filters, hoses that leak air bubbles, or a bad pick-up tube. The only cooling the injection pump has is the fuel and if the supply is interrupted the pump is cooked very quickly. There are no new VP44 injection pumps, so you need to purchase a rebuilt if it has failed. Again, go to one of the site sponsors and get a good quality pump. Just do not replace the pump if you have not replaced the flexible hoses and the pick-up tube, or the lift pump is faulty, as you will just fry the new injection pump in short order.

Once everything is fixed, keep the fuel treated, the hoses changed frequently, the filters clean, and a properly rebuilt VP44 will outlast the truck body.

 

it happens to most of the early 24 valves. the injection pump control module has failed, the code will be po 1693, 1688, and 1689

 

Thank you for the good advice. I discovered last night that the key switch code trick doesn't work on my truck. Also, last night, I pulled the line off of the fuel tank side of transfer pump and submersed it into 1 quart of clean fuel and bumped the starter to activate the pump. The pump motor ran for 25 seconds as it should, but id didn't pull any fuel from the container. I thought maybe it needed to be primed to work correctly, so I attached a funnel to the hose on the inlet side of the transfer pump and poured about a pint of clean fuel into the funnel and again bumped the starter to activate the pump. When I did this I noticed fuel leaking from some where, but not at the inlet connection where I was introducing the fuel. I think my transfer pump is bad.

 

Following your advice, I was able to troubleshoot and diagnose the problem over the weekend.

I could hear the transfer pump running, but because the fine folks in this forum advised that the pump could be running but not pumping, I decided to test the transfer pump.

To test the transfer pump, I removed the fuel line from the inlet side of the pump (the side connected to the fuel tank), secured a clear vinyl tube to the fitting on the pump and submersed it into a container of clean fuel. I bumped the starter to activate the pump, but the pump only lifted the fuel to the top of the container. I repeated the process 3 times, before pronouncing the transfer dead. I purchased a new one, installed it and repeated the procedure above. I was pleased to see the replacement pump lift the fuel from the container and into the filter. I reassembled everything, bled the injector lines at the cylinder head and voila!, she came to life.

I guess I am one of the lucky ones, as the injector pump is still functioning properly.

Thanks again,

ruet66

 

Good Job!!! Glad she's running again!! Take care and have fun!