I have a 99 Dodge with the 24 valve Cummins. I also run the Banks power pack which is the greatest thing since sliced bread. Recently I have picked up a miss fire when accelerating hard, but it’s not all the time. I smell diesel fumes and found a small amount of fuel dripping from the bell housing. The dealership is trying to tell me I need a new injection pump. Although they will not tell me what test they used to determine it is the injection pump. “They” say it has an internal leak but how would “they “know? It sounds like I sucking air in from wherever the fuel leak is and that causing the miss fire. Can anyone give me the straight skinny on this? Oh and by the way the VP44 pump on the truck now is less than two years old.

 

check your injector lines where they connect to the head, especially the rear ones...... it sounds like you may have a loose connection or a leaking line

 

I agree with JohnH

On my '99 I replaced NUMEROUS cracked injector lines over the time I had the truck. I think 4.

I would start there.

Doubtful that a failing pump would be leaking fuel externally, but that's just me.

Maybe check the fittings on and around your lift pump as well, leaks back there could drip onto the bellhousing.

 

Help me out... where is the lift pump? is come off the tank?

 

lift pump is on the block under/behind the fuel filter canister... unless you have had it recently replaced by the dealer... "new" fix by dealers is to relocate in tank

 

Can the Injection pump cause this kind of miss fire Intermittently or is it all or nothing?

 

The 1st thing to do with a diesel when there is a running issue is a fuel pressure test ?
Check all fuel lines & hoses front the tank to injectors , from tank you need to pressurize the tank , 2-3 lbs then look with a mirror & flashlite .
If there is a leak , air getting into the system can make the engine miss .

 

So my next two questions would have to be how and where? How so I pressurize the fuel tank and where I'm I should I look for the leak? Help I need to get on the road again.

 

I got an old fuel cap , drilled a hole to the size that screwing in a tire valve was tight , added a little silly cone to help seal , put cap on fill neck , use a gauge so you do not over pressurize the tanks [ 2-3 lbs ] then with a flash light & mirror , check every part of all hose's , lines and connection for fuel , all the way to injection pump , after that the injection pump will make pressure , then check a lines from injection pump to injectors , do not miss a inch of any , that may be where there could be a leak , in the hardest place to check [ Murrphy's Law ] .

 

You may want to mention where your are , there maybe a member in your area that can help .

 

I'm in las vegas

 

You said that fuel is leaking on the bell housing, check the fuel return line behind the head and valve cover around the backside of the engine. Look in the link below, go to post 2(diagram) items 9 and 2.


https://www.dieseltruckresource.com/...ensor+location

 

If I'm leaking from there, could I also suck air causing the miss?

 

Leaks go both ways , like on my truck , the lift pump is on the engine , so from eng. to tank is a vacuum - sucking air [ I would not see the leak , thats why pressurizing fuel tank , then I could see wet from fuel ] vacuum can make it run bad/miss , if you have the lift pump in tanks , it would have pressure .
Around the back of the head there maybe both lines with pressure and vacuum [ if LP is at eng ] .

 

I don't have a 24 valve so I'm probably wrong, but isn't the lift pump (electric) on the frame rail on a 99?