Need some clue how to start diagnosing my Cummins diesel 5.9, 2002 Dodge Ram 2500, with 58,000 miles (low mileage because I mostly just use it to tow my boat). Ran great for first ten years until this weekend. Engine suddenly started running rough, knocking, and slowing down. I nursed it home by running slowly. Sometimes it sped up slightly going up hill. Today I changed the fuel filter, but the fuel in the canister was clean and water free. That didn't fix the problem. Runs ok while idling down the street, but engine quits altogether when I give it more accelerator. I was able to restart it several times, but it still quit frequently.

I noticed the following displayed on the dash where my odometer reading normally is (in this order):

P ECU
P0216
P0230
P Done

P PCU
P 1693
P Done

I'm afraid to just drive it to a repair shop, because it keeps quitting in the road. I'm a former tech, and could probably do some diagnosis with guidance (and teh proper reader), but have little experience with late model, electronically controlled engines. Any help on how to attack this is greatly appreciated.

Svenfran

 

p1693 is a companion code. means there is another code in there that can not be displayed without a code reader plugged in.

P0230 = your lift pump is dead. ECU is either reading too high or too low of amperage/voltage from the pump indicating that it has failed, which makes sense as you have the P0216 code which means your injection pump timing is failing.

STOP driving the truck immediately! don't even start it till you fix that lift pump!

you are severely damaging the injection pump by driving it without a lift pump...its like running an engine without an oil pump or water pump...the fluid is there, but its not doing its job because its not being circulated therefor causing overheat, lack of lubrication, and lack of supply flow to keep the engine running above idle...

you will be damn lucky if you can replace that lift pump and the injection pump does not fail, but it may already be too late for the injection pump...you won't know until you replace the lift pump.

I also urge you to get a fuel pressure gauge. this could have easily been diagnosed before it was a problem if you had a fuel pressure gauge (mechanical 0-30psi gauge)

fuel pressure must ALWAYS be between 10 and 20psi under any throttle conditions or idle. if it ever gets below 10psi means either the lift pump is failing, or the fuel filter is clogged.

replace your lift pump first as that has 100% for sure failed. something aftermarket rated at 95/100GPH or higher would be preferred.

 

Thanks, Jigabop. It may be a couple of weeks before I can get to the recommended repair and report back, due to the holidays, but I'll do that for the benefit of anyone else who may read this thread. As additional background, I let my usual high standards for PM slip on this. The fuel filter I just changed out was several years old and had 31K miles on it.

I think I mistakenly assumed there was some warning system for filter restriction that this truck apparently does not have. And on the water-in-fuel light that never came on. And on the fact that it ran great until the moment that it depowered and started running rough. Fortunately, the fuel was clean and water free, but the old filter was pretty black. My bad; lesson learned. And I hope I haven't trashed the injection pump, but time will tell after I replace the lift pump.

PS- I recall hearing from a Cummins rep years ago that the newer ultra low sulfur diesel (ULSD) might lead to lift pump failure, but never did anything about that. Wonder if he was right?

Thanks again, Svenfran

 

OEM design leads to lift pump failure.

they put the lift pump on the engine block right next to all of that engine heat. not to mention the lift pump is as far away as possible from the fuel tank making the pump work twice as hard to move fuel. pumps can push fuel easier than they can pull it. so the ideal solution would be a frame mounted lift pump that is close to the fuel tank.

anyway for a good future warning system, I suggest an isspro 0-30psi mechanical fuel pressure gauge with a tapped banjo bolt, a needle valve to act as both a water hammer snubber, and shutoff, and 1/8" airbrake line from napa to plumb the gauge as airbake line is fuel/oil rated and has a much higher burst pressure than poly line so it will last 10x longer.

plumb that in the the fuel filter outlet that leads to the injection pump, and that will tell you the fuel pressure the injection pump is seeing. it will also tell you when your fuel filter is becoming restricted and needs changed.

as for ULSD, it can cause injection pump failure over time due to its lack of lubricity.

this chart shows additives that work/don't work to improve lubricity in the fuel.

I run wally world 2cycle oil at 128:1 mix or 1oz per gallon which is more than the chart shows.

here is pump wear vs lubricity by bosch

 

Good information on lubricity. I have been using the Diesel Kleen product in my truck, but would like to move towards a bio-blend. Any thoughts?

 

some stations sell B5 soypower. (5% bio 95% petro)

bout the easiest way to run it.

or just run an additive.

I run wally world 2 stroke oil at 128:1 mix (stronger mix than on the chart)

 

Successfully repaired. Turned out to be the fuel transfer (lift) pump mounted on the engine. Its electric motor simply wasn't running. I replaced it with a Raptor FRRP replacement that mounts to the same location (much easier than the Dodge in-tank solution). I also bought a fuel restriction warning system. Both came from www.bluechipdiesel.com, who were very helpful on the phone. Very impressed with the pump, kit, and instructions. It appears very beefy. It's a rotor type pump and has a four-year warranty. Took about three hours start to finish (I'm slow and don't bend like I used to). Truck now runs like a top again, with no current evidence of injection pump damage from the earlier lack of full fuel flow, but time will tell.

One interesting note from bluechip is that the truck will run without help from the lift pump, but the injection pump can't pull enough fuel to produce much power above idle. And that the failed OEM pump on my year model (2002) actually creates some extra restriction that makes the situation even worse. Original symptom was the the truck would idle, but then die when trying to accelerate, then restart after a while. Thanks to those who weighed in.