I'm having a problem with the truck stalling when I put it in gear and a couple of guys suggested I look at air getting in to the injector pass thrus. These are the connectors that carry the fuel from the high pressure line through the head to the injector.

I have a couple of questions about these pass throughs.

1. If it is loose how can air get in? Would not fuel come out?

2. I dragged the injector across the tips of these pass thoughs and they are deformed a tad (shinny on the end), but they look like the seats are just fine, no scratches on them. Do I need to replace them?

3. How many seals are in these things? I can see only one o-ring on the shaft inside a groove, but the Cummins parts drawings calls out one on the tip between the injector and the pass through? That can't be right! Can it?

 

You won't get air in the system with loose HPCs but you will lose pressure through the joint if it isn't seated properly. They need to be torqued in pretty well in order to seal well. Seat the injectors in, and make sure the HPC lines up well with the correct spot on the injector and then be sure they are torqued well and you should be good.

 

Thanks Flash. I just got done pulling them all out and replacing the o-rings since I had them out. I reinstalled them and fired the truck back up. Still stalls when I put it in gear so I'll keep looking for air getting into the system.

There is just one o-ring in there right?

 

As far as I know.

 

99's had a change order on them I think. They were changed out to the ones we use on newer trucks. Call a diesel shop.

 

Wouldn't be a bad idea... that's a very precise fit in there and any deformity could cause an issue.

 

Well, I pulled them all and reinstalled them using torque specs from Midwest Injector Service, and I replaced the fuel line gaskets. No joy. She still stalls when I put it in gear.

What is odd is that sometimes the truck stalls and sometimes it does not. It seems to stall easier after idle a few minutes. The RPM drops to below 500 and stalls, then after restart it goes right into gear with little to no RPM loss.

What are the chances of the new injector pump being bad?

 

Watch your engine oil level. Chances are very good that you are in fact leaking fuel from that joint if you are seeing some wear on the tips. The oil level will climb and reek of raw fuel if you have a problem.

 

can you post a picture of the tips of your connector tubes?

 

Have you checked to see what codes are present?

 

Sounds like an electronic issue. If they were leaking, it would be a hard start issue, not a stall. You would also likely have a miss. Leaking connector tubes won't cause engine oil to rise, that would be leaking injector o-rings.

 

Just curious if the TC is new?

 

No codes at all.

 

Nope, same ol TC. Nothing has changed except the VP44, & injectors. I put in a stock VP44, and stock marine injectors.


Some times it stalls, some times it don't. The first part of the day, (cold engine) it seems to happen more. I'm starting to get used to it now, but it is a PIA!

 

What converter do you have of Daves?