Strange diesel problem 3500 Dodge

Billy Shafer

Well-known Member
I have a 1999 3500 that has started acting strange. It will start just fine run five to ten minutes stumble and die. Wait five minutes and it will start again. Do the same thing again. Has new fuel filter and fuel pump. But it was doing this before they were replaced. When it does start it will start just fine. I think everything is pointing to the injector pump. But that doesn't seem right. As it will start just fine.

I need this truck in the worst way. My only way to get to my docs office and my meds. Plus the normal things. Anyone ever seen this.
 
Check the battery first. It should have at least 12.5 - 13 volts at idle. Any less and it will shut down. Don't look at what the voltmeter says on the dash. Check the voltage at the batteries.

Next have the Idle air Control motor checked.

Simplest thing to do. Take it and have it hooked to a computer that can check it out.. I have learned the hard way that chasing gremlins in modern automobiles is an expensive way to fix a $2.00 problem.
 
Thanks but I don't think it could be the first two. It will rev up just fine. Idles like it always has. It will have to be towed to a
computer. No way it will make it on it's own.
 
Stock fuel pump, or after market performance system (air dog etc)? Check the fuel pump relay, went out on my old '99 ISB Dodge. Harbor freights code readers are decent, and cheap, just make sure to get the top one or two that allow you to look at individual sensor data. No use spending thousands on a name brand one for few times a year use.
 
Perhaps the Fuel solenoid (assuming it has one...if so, is failing, heats up and quits working 'til it cools off a little).
 

Quick hits easy checks no different than what you are use to...

Sounds like air leaking into lift pump lines or a leak in the pickup line in the tank. Any air entering the system will keep it from flowing fuel since it compresses and acts like a shock absorber. You can check it using a clear line with a vertical loop in it between the filter and the main injection pump.

I like to convert them to a in-tank pump

Chryslers fix for that was to install an in tank fuel pump

these truck had a engine mounted lift pump ,that pulled fuel from the tank. and they had many problems , the replacement pump is in tank mounted, and you have to buy a "kit" from chrysler to add the wiring and and relay to power the new in tank. also the kit adds a jumper connection to replace the old block mounted pump. the old style system works as long as it has a clean tank and strainer, and a good pump, and no air leaks on the "vacuum" side of the pump. priced for this kit total was like 800 bucks. Its not a bad job to convert the tank has to be dropped other that that work thru the left fender well plug and play.

You could also add fuel to the tank if a pick up problem get the fuel above the leak at the pick up in tank.

I am not a diesel mechanic I am going to assume it has a engine mounted electric fuel pump even it it has a mechanical pump the pump needs to be checked NO SCANNER NEEDED.

Quick hit off the net.

Not to beat you up, but you have an ECM for fueling controls (ds engine mounted). The PCM (jtec)--pass side firewall behind air filter.. handles controlling non- engine mmmgt functions.

Locate lift pump dongle/connector (two pin male duetch connector) near where factory pump would have resided on the ds of engine block works as follows.

Key on should buzz/trigger the pump 1-2 seconds, bump the key (think bumping an old gas engine for tdc so the distributor would align)allowing ign key to return to run..lift pump should have power for 20 secs. +/-.

Look at your 50 way ecm pin out, you will notice two pins drive the lift pump, one pin is to create voltage drop during cranking, the other supplys power to lift pump at all times when engine is running, both splice before the lift pump connector. The ecm powers the lift pump and should have run through a relay, but many have lasted hundreds of thousands of miles.

If it doesn't power the lift pump directly from the battery check for proper pump operation independant of the ecm control.

If this solves problem, and the customer is cheap not wanting to buy an ecm due to one fault..lift pump driver inop. Just wire in a 40 amp relay to ign run for lift pump control. If the safety issue concerns you tap the oil psi sender (near ps pump reservior) for a signal to your relay coil, then if the truck is an accident and engine stops running the power to relay is interupted stopping the lift pump.

What he is saying the pcm controls the pump check power to the pump you can bypass the PCM to run the pump. I would need the Vin # to research it more as I am not sure what system it uses. Checking fuel/fuel pressures and fir air seams easy enoufh. Lets hope a real diesel mechanic checks in until them treat it like anyother engine you are use to working on. :wink:
 

One more thang

I have seen them run for mouths with the electric pump disconnected from a repair are other issues that caused the connector to come loose. Once a problem arises form fuel pressure all I had to do was plug the pump back up :shock:

I guess the injector pump was able to keep the system primed without a lift pump...
 

Wild card.. these are know to have a poor ground cable under the battery tray that corrodes and causes problems.
 
Crank sensor and ignition switch are a common cause of intermittent problems on your truck.

There is a good reason why most parts places usually have a dozen of each in stock.

Both fairly easy to change.
For the ignition switch if you do not own a driver for the tamper proof torx screws (the ones with a pin in the middle) you can use a small flat blade jewellers screwdriver and a small hammer to snap the pin off then you can use a normal torx to remove it.

Less common but another cause of an intermittent fault I have repaired on those was loose connections on back of fuse panel.
 
This what I have found so for. After engine stops. Fuel to pump,filter and injection pump. Engine will crank up and start fine then die. Fuel at all places except Injector lines. So I am thinking fuel is being shut off at the the injector pump. Bad relay or control valve. Thanks for all the help.

I have been a diesel mechanic all my life. 68 now. Worked in control systems for fifty of those years.Really makes me feel bad that I can hardly do what I use to. I can still do some work but I am slow.
 
I have had crank sensor problems, but that usually just killed the engine instantly, so think it may be fuel issue also.
 
I agree with SVCummins. Go to www.tdr1.com. Have been a reader there to several years. Very smart and know how DODGE members. They have helped me make my 96 3500 a truck I can't wear out. Owned it 20 yrs and still going.
 

Do you have a fuel pressure gauge, if so how much fuel pressure is the lift pump making?
99 Cummins 24 valve has a computer controlled injection pump that is feed by an electric fuel pump mounted on the frame.
The electric fuel pumps are known to go bad but the injection pump will continue to pull fuel and keep the engine running, but in doing so the inj pump will eat itself up.
I have a BIL and cousin that have 99 and 2000 model Cummins powered Dodges, neither had gauges and both had the electric fuel pump fail, both ended up having to replace the electric fuel pump and inj pump.
Without a gauge you won't know the electric fuel pumps fails until the injection pump starts giving trouble.
Electric fuel pumps are fairly cheap, a rebuilt VP44 injection pump will cost you around $1000.
Don't waste your money on any of the high dollar electric fuel pumps like a FASS, it won't last any longer than a good stock replacement, but defiantly install a fuel pressure gauge to monitor the electric pump before the injection pump becomes damaged.

FYI, early 98 12 valve Cummins were the last to have mechanical lift pumps, I have a 97 model 12 valve in my F-450 with a mechanical lift pump, very trouble free system, no electric fuel pumps for me.
 
I just replaced the fuel pump. When it starts it runs fine. May run five minutes or thirty minutes just fine. Then stumbles and shuts
off. Wait a few minutes and it will start up and do the same thing. Feeling sick today so I am taking the day off. If it is going to
take much money. I am SOL.
 
Hope you got it fixed, but if not I think I had the same problem with a 98 24 valve.
It would run fine then quit even while idling. I had a pin pushed through the ground wire on the connector to the VP44 and when it quit I had 12VDC on the ground wire. Ran a new ground wire directly to the Neg. connector on driver side battery and no issues for 3 years.
That ground wire goes through a bunch of connectors.

Blue chip diesel site troubleshooting page and staff were a big help. They suggested monitoring the ground wire.
 
Hope you got it fixed, but if not I think I had the same problem with a 98 24 valve.
It would run fine then quit even while idling. I had a pin pushed through the ground wire on the connector to the VP44 and when it quit I had 12VDC on the ground wire. Ran a new ground wire directly to the Neg. connector on driver side battery and no issues for 3 years.
That ground wire goes through a bunch of connectors.

Blue chip diesel site troubleshooting page and staff were a big help. They suggested monitoring the ground wire.
 
Keep in mind, on the 24v if it has been starving for fuel then the injector pump will not last very long. This problem is about the only notorious problem on the 24v. It's been explained in earlier posts about lift pump problems and fixes so keep that in mind. There are plenty of aftermarket solutions to monitor fuel pressure or install an idiot light when pressure is low.
 

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