2004 Dodge Ram 2500 - 5.9L Dsl Low Power

[nokomisauto]

2004 Dodge Ram 2500 5.9 Diesel. This is the diesel that we put new injectors in for the hard starting - resolved hard starting problem. We are now experiencing low power around 30 - 40 mph. Excelerate hard - feel transmission shift down a gear and cannot hear turbo run and it sounds doggy. This is a early built 2004 - build date of July 2003. I am questioning the lift pump because of the previous condition. This pump continuously ran and I'm thinking its weak and the flow is poor. There is no black smoke or gray or white smoke. Has new reman mopar transmission installed. Truck has 139,000 miles - no codes! By scan tool, fuel pressure reads good by manufacture specs. Has anybody experienced this problem and what was the fix? The computer was flashed on 7-19-2004 for starting and power problems. The power problem came in when he started having injector problems over a year ago.

[steven kiser]

i have a 2500 with a 5.9 and ran into a huge problem with the lift pump. if the pump is mounted on the engine l/r there is an updated pump that goes into the tank.

[Tim Martin]

If the lift pump needs to be replaced there are better options than the one that the oem is putting in the tank. I know that there are shops that will take issue with that but we do not put the pumps in the tank. Too many problems with that one. Pump suppliers such as FASS or Air Dog would be better choices.

In this vehicle I tend to feel that the issue is not with fuel supply. Rather a sensor out of range on the engine. I have seen some of these get pretty far out a specs and not set a code. Which sensors? Coolant. Air Temp, Fuel Pressure. And there are others. Could have a faulty cam sensor. I'd be putting my lab scope to work on this vehicle.

[steven kiser]

on one aspect i agree with tim. there may be another issue besides the lift pump. i quick way is just unplug it momentarily and see if it effects the performance. if the pump is functioning you'll see a drop off in power. if not then you'll notice no difference. as far as the after market lift pump goes i've tried both ways (more than once) and resided myself to use the factory update. there are viable options to replace the lift pump that i'm sure work fine but being an old time mechanic/tech i tend to believe that if a different pump would work then the manufacturer would have used it in the update. i know that we all know that manufactures always don't make the correct decision and i'll bow to the techs that are more dsl orientated. i will add that i've seen senders replaced in the tank and have used the updated assembly while the lift pump is still activated on the motor. a huge no no and will cause stumbling and lack of power issues. the impeller on the updated module will on occasion block the flow of fuel causing a power issue. this i have experienced on more than one occasion. i stumbled upon it because it reminded me of issues that were caused by adding electric pumps in line instead of removing the tank. this was a practice when in tank pumps started to pop up. years ago , aging myself. some shops weren't going to remove the tanks and just put in line pumps in and powered it up through key on power lugs.

[mopwrforme]

Well I'm new to the system.

If the truck still isnt fixed, keep in mind Cummins is big on volume not pressure. If I'm not mistaken, please check the spec; I believe it's 750ml in 30 sec. pre filter. Also, if there is a 5 psi drop between the in and out of the filter, it would need replaced. One more thing; check the turbo output via intake pressure sensor. You may have an intercooler leak. Good clue would be excessive noise on acceleration.

No, I'm not going to attempt the sound .

[Tim Martin]

Welcome to the forum. You will find it a friendly place to exchange ideas an help.

Any progress on this dodge truck?

[steven kiser]

ditto...................

[protraxrptr17]

Check to make sure you got the fuel lines mega tight where they go into the head. If not, there can be a leak between the connector tube and the injector. It leaks into the return so you wont see it. Put actual rail pressure and desired rail pressure on a graph and watch it during the low power condition. Should follow pretty close. I keep a brand new regulator on the shelf for test purposes. See alot of these fail and its real easy to change. Three torx screws, it's mounted on the back of the HP pump. It helps to figure out if the pump is bad or the reg is bad.