1999 stalls at stopping

[George99]

I just replaced the vp44 injection pump and lift pump, now it stalls when pushing in the clutch when coming to a stop. Rpm will bounce around sometimes you can keep it from stalling by giving it fuel and pushing the clutch in. It never did this before, I had a p0252 code is the reason I changed out the the vp44. The new lift pump is a OEM. Vp44 is a remanufactured. 

[Me78569]

how many miles on the injectors?  

[George99]

120k

10 minutes ago, Me78569 said:

how many miles on the injectors?  

 

[Me78569]

how's fuel pressure to the VP?  
 

any leaks in the fuel supply?   

[George99]

14 psi at idle, 7 @wot, no leaks 

[Me78569]

I'd be looking at the injectors personally.  

 

If there were no codes present

[Dieselfuture]

I'd also be looking at better lift pump 

[Hawkez]

Is the code still present?  You certainly need to upgrade your lift pump.  Are the RMPs jumping when it is sitting idle.  It is odd that it is stalling when you push the clutch in, is this as you are traveling down the road or sitting still?

[pepsi71ocean]

I'm going to disagree with the consensus here and think you should check your grounds. I had a truck up here throw 252(251, maybe), and it was a ground cable that came loose. 

 

Since you've replaced the VP I'm going to say that this is possible. If it was Injectors I would think that he should have stalling at idle reguardless if he started it up.

Edited December 28, 2018 by pepsi71ocean

[George99]

I just replaced the apps and nothing, still a dead pedal and dying at stops, I've checked the ground and wiring nothing wrong. 3 weeks and I still can't get to work, should I take it to a Dodge dealer or Cummins? It amazes me that I have taken it to 2 shops and no one can figure it out. But they took the money. Good mechanics in Denver are rare, living in a metropolitan area with 2 million people and not one shop can figure it out, 30 yr. old technology, I'm pizzed off. George. 

[Guest 04Mach1]

I'll be in Denver on Friday, well actually east Aurora, E470 & Colfax area. I'm actually in the process of moving back to Aurora, Colorado. Maybe we could schedule a time and I could check it out.

 

So by your description of the stalling didn't start until after the VP was replaced is there a chance the VP gear got moved a tooth hence making the injection timing off? I worked on a first gen VE a while back and found when the owner replaced the VE pump he somehow moved the VE gear a tooth which was retarding the timing. Engine still sounded good but was sluggish off idle and would die when stopping. If timing is correct I'd have to say that the last part replaced before the problem showed its self is likely the cause for the stalling. Like @Me78569 stated injectors could be part of the cause although I've never really seen it without a couple of dead cylinders. My truck got a very erratic idle when the injectors were getting bad at 100k miles.

 

As everyone else stated you need to get a lift pump that supplies a reliable 14-20 psi under all driving conditions. 7 psi is way too low. I personally prefer Airdog or Fass. I don't have much experience with Fuel Boss so I can't comment on it.

Edited January 3, 2019 by 04Mach1

[pepsi71ocean]

3 hours ago, 04Mach1 said:

I'll be in Denver on Friday, well actually east Aurora, E470 & Colfax area. I'm actually in the process of moving back to Aurora, Colorado. Maybe we could schedule a time and I could check it out.

 

So by your description of the stalling didn't start until after the VP was replaced is there a chance the VP gear got moved a tooth hence making the injection timing off? I worked on a first gen VE a while back and found when the owner replaced the VE pump he somehow moved the VE gear a tooth which was retarding the timing. Engine still sounded good but was sluggish off idle and would die when stopping. If timing is correct I'd have to say that the last part replaced before the problem showed its self is likely the cause for the stalling. Like @Me78569 stated injectors could be part of the cause although I've never really seen it without a couple of dead cylinders. My truck got a very erratic idle when the injectors were getting bad at 100k miles.

 

As everyone else stated you need to get a lift pump that supplies a reliable 14-20 psi under all driving conditions. 7 psi is way too low. I personally prefer Airdog or Fass. I don't have much experience with Fuel Boss so I can't comment on it.

 

Its been a while, but I don't think that the VP44 can jump a tooth or even in the gear housing. now if the key-way is in backwards, i can see that. However in order to check that you'd have to pull the cover. 

Have you put the truck in neutral when coming to a stop to verify that its not the transmission?

[Guest 04Mach1]

There is enough room in the gear housing to wiggle the VP gear around and it is possible to move it a tooth. I've seen it happen in commercial VP applications like box trucks.