Best cp3 for a 400,000 mile duramax?

randal07

another guy with a truck
Joined
Oct 2, 2011
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I just acquired a 2002 2500 with around 400,000 miles. About 2 years ago the truck lost power but was still drivable, so the original owner drove until now. It still runs and hasn't lost any more power, but after verifying, I found that it needs a new injection pump. So my questions are, who is the best vendor to get a new pump from, what is the best pump to run on a stock truck that will give it a little more pep and does anyone want to make a bet on how long the factory injectors last after they get some actual rail pressure?
 
If you are cheap, buy a low mile lbz pump $300-500.

If you buy a new pump, either Fleece cp3k or exergy sportsman.
 
I'm leaning towards exergy sportsman. What are the benefits of the lbz pump other than price?
 
They have slightly more displacement than the older pumps. Exergy sportsman and Fleece pumps start life as lbz pumps.

You will need to rescale the fpr table if you run the lbz regulator in an older truck like yours.
 
I wouldnt waste the time buying a performance pump for an old engine with that many miles.
Just buy a new replacement CP3 (most are LBZ-type nowadays) or install a known-good used pump, put a new LB7 regulator on it and drive the truck.
 
Don't waste the money on a performance pump for a stock truck. Get a reman Bosch pump and injectors. The typical life span of an injection system is 150,000 miles. The pump does not affect the life of the injectors unless it is coming apart.
 
Damn, if life span is 150,000, its doing pretty good for almost 400,000 with factory injectors and pump.
 
Also, the truck most like wont stay stock. I'm assuming that the injectors will sh!t out after it gets a new pump so ill just go with bigger injectors and id like to have a pump to support it. My main question is, what vendor should I go with? I've had good luck with exergys customer service on my Cummins, but the price is kinda strep. I'd also like to support a forum vendor if possible.
 
Damn, if life span is 150,000, its doing pretty good for almost 400,000 with factory injectors and pump.

Huck was talking about the LB7 injectors. They dont last for crap.
Cp3 can go a long time more than that.
 
If it's not staying stock I'd throw a lift pump on it. Have had luck doing that to "nurse" couple trucks along. Always suppose to be temporary but they never came back for cp3 issues.
 
If it's not staying stock I'd throw a lift pump on it. Have had luck doing that to "nurse" couple trucks along. Always suppose to be temporary but they never came back for cp3 issues.

Did you use the lift pump to help with low actual rail pressure? Because that's the problem im having, actual rail pressure is way below desired.
 
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Huck was talking about the LB7 injectors. They dont last for crap.
Cp3 can go a long time more than that.

150,000 miles is the average life span of a common rail injection system, not just the LB7. The nozzle tips erode over time and the fuel spray gets distorted, mileage drops, and over all performance weakens. I have seen many go longer yes. It really depends on the fuel quality.

PS The issues with the LB7 injectors have been addressed by Bosch a while ago. The bodies and check balls are much better and the original problem is no longer.
 
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