Attention: TDR Forum Junkies 
Matt42
TDR MEMBER
Well, I'm back after a hiatus with a peculiar issue with my 2004 work truck. It's a 3500 Quad Cab 4x4, dual rears, 4.10 axles, 6 speed 5600 transmission. Apart from a water pump that came unglued on a Colorado mountain pass downgrade in 2012, it's been amazingly trouble free. That 12 year run ended three weeks ago on another mountain road, equally narrow and winding, uphill this time, and out of state again, when the truck abruptly quit running. Just. Stopped. Running. It was as if someone had stuffed a pencil into the fuel line. I had been driving it up a state highway grade of about 8% and pushing it hard to get back to town before dark. Luck was with us and I was able to coast into the only gravel turnout for miles. With my crew, I had just dropped a 10,000 lb work trailer in a remote area. The truck was at about 8,000 to 9,000 lbs itself.
I'm well aware of the fuel lift problems with this model year, but at 64,000 miles I had expected a little more time. One of the crew has a son who is a diesel mechanic in yet another state, so he called. Lift pump and injection pump were the long-distance diagnosis, but the low mileage was surprising. I called and had the truck flatbedded to our motel, and then flatbedded the next day to the only place that was open that said they worked on Dodge diesels.
They ran some tests and confirmed that the lift pump was shot. The lift pump got replaced with an aftermarket model made by Precision Pumps. The shop's mechanic took it on a decent test drive, and I came to get it. It started and ran fine. Not really believing that we got away with just the lift pump, I ran a half dozen local errands. At the end of the last errand; about 12 miles and maybe an hour, it quit running again. But this time I had some warning, as if it was running out of fuel. I was of course blocking traffic this time. If I let the engine cool, I could get it to start and run for maybe 10 seconds, so I was able to get out of traffic while waiting for the flatbed. And back it went.
The story I got was that (1) the first replacement fuel lift pump was definitely defective,
and (2) they had ordered it using an obsolete part number. I was told that Chrysler had a TSB or some such out that replaced that part number with a newer version pump that included a replacement wiring harness that provided additional amperage to the lift pump, as well as more sustained pressure. Ohh kay, I thought, but I was a long way from home. I had them put in the for-real MoPar branded pump and harness which of course cost more. It took a while to get it delivered, being in a city far away. Then I asked their mechanic to give it a really hard shakedown this time, which he did.
The outcome was that it ran fine. I was able to get the work trailer out of the back country, which included some 10% and 12% upgrades. And I was also able to drive the 1,000 miles home, pulling the trailer (circa 20,000 lb GCVW) with no hiccups of any kind, getting the usual 11 mpg.
Before the OEM lift pump quit, there had been NO indications of any problems. No change in fuel economy. No reduction in power that I could feel. No increase in EGT. No hiccuping or burping at speeds. No surging. It started and ran normally. A couple of cranks and it was ready to go every time. Then on that upgrade, it just stopped running. We have kept this truck about four years longer than normal, in part because of the low miles. And also because I threaten to chain myself to it when anyone talks about auctioning it off. (As you might infer from my signature line, it belongs to my employer, not me. And it has literally saved my life twice.) It does not have a lot of miles on it, but it is a special-purpose truck in the fleet. When we use it, we use it HARD and in really ugly places.
Now to my question: Did the original lift pump just abruptly quit without taking the injector pump with it? Or should I be looking at a new injector pump soon?
I'm well aware of the fuel lift problems with this model year, but at 64,000 miles I had expected a little more time. One of the crew has a son who is a diesel mechanic in yet another state, so he called. Lift pump and injection pump were the long-distance diagnosis, but the low mileage was surprising. I called and had the truck flatbedded to our motel, and then flatbedded the next day to the only place that was open that said they worked on Dodge diesels.
They ran some tests and confirmed that the lift pump was shot. The lift pump got replaced with an aftermarket model made by Precision Pumps. The shop's mechanic took it on a decent test drive, and I came to get it. It started and ran fine. Not really believing that we got away with just the lift pump, I ran a half dozen local errands. At the end of the last errand; about 12 miles and maybe an hour, it quit running again. But this time I had some warning, as if it was running out of fuel. I was of course blocking traffic this time. If I let the engine cool, I could get it to start and run for maybe 10 seconds, so I was able to get out of traffic while waiting for the flatbed. And back it went.
The story I got was that (1) the first replacement fuel lift pump was definitely defective,
and (2) they had ordered it using an obsolete part number. I was told that Chrysler had a TSB or some such out that replaced that part number with a newer version pump that included a replacement wiring harness that provided additional amperage to the lift pump, as well as more sustained pressure. Ohh kay, I thought, but I was a long way from home. I had them put in the for-real MoPar branded pump and harness which of course cost more. It took a while to get it delivered, being in a city far away. Then I asked their mechanic to give it a really hard shakedown this time, which he did.The outcome was that it ran fine. I was able to get the work trailer out of the back country, which included some 10% and 12% upgrades. And I was also able to drive the 1,000 miles home, pulling the trailer (circa 20,000 lb GCVW) with no hiccups of any kind, getting the usual 11 mpg.
Before the OEM lift pump quit, there had been NO indications of any problems. No change in fuel economy. No reduction in power that I could feel. No increase in EGT. No hiccuping or burping at speeds. No surging. It started and ran normally. A couple of cranks and it was ready to go every time. Then on that upgrade, it just stopped running. We have kept this truck about four years longer than normal, in part because of the low miles. And also because I threaten to chain myself to it when anyone talks about auctioning it off. (As you might infer from my signature line, it belongs to my employer, not me. And it has literally saved my life twice.) It does not have a lot of miles on it, but it is a special-purpose truck in the fleet. When we use it, we use it HARD and in really ugly places.
Now to my question: Did the original lift pump just abruptly quit without taking the injector pump with it? Or should I be looking at a new injector pump soon?
