Replace Injection Pump?

[phn@mnr]

Hello All,

I recently replaced the right bank of injectors on my 02 LB7. This was the first time and at 140,000K miles. 5 and 7 were running between +6 and +8 on the balance rate and we had recently had a cross country trip during which a fuel leak started sometime in the 2nd 2000+ mile nonstop leg. The oil pan was full and the mix coated the underside of the chassis. The good news, I suppose, is that no unusual wear metals were found in an oil test. Viscosity was way way down. This was about 8K miles into a Rotella 5w-40 synthetic change.

The leak turned out to be the #5 injection line rusting out at the injector fitting. After bead blasting everything, it was clear #5 had to be replaced. Those lines are not cheap. So, while I was in there, I replaced all 4 right side injectors, the #5 line and cleaned up the whole thing. A little cleaning and painting of brackets and it's back to running well.

I ran the GM test for internal fuel leaks after it was all back together. The final check is to command the pump to 160 Mpa and run it as idle for 10 minutes. No leaks. Yeah! However, the pump was not able to reach 160 Mpa. It ran in the 125 - 126 Mpa range the entire time. I ran through the pump testing section and it calls for a low of 145 Mpa. So, the question is; should I replace the injection pump now? Is it heading for a quick failure? Can I predict how long it might last?

The truck is mostly used for very long cross country towing. I'm going to replace the left bank before it takes a long trip.

Thanks for any assistance,

Paul

[Kennedy]

It's tough to condemn the pump for lack of pressure without having a set of known good injectors.

Not sure how the #5 line rusting could allow fuel into the crankcase as it is oring sealed to the injector itself so all leakage should be external.

As far as I am concerned, the lines cannot be properly cleaned once rusted so when we do an injector job I insist on doing all 8 lines fresh. Bead blasting can be quite risky as well. Loose bead dust and grit can be tough to completely remove, and I'd almost bet that under a microscope you would find beads embedded in the metal.