My experience with these DB2 pumps in GM 6.2l diesels is that you'll notice one of two things: Either the engine will start normally when cold but start very hard or not at all when warm, or you'll start noticing a power loss while driving and within a couple hundred miles it won't run any more.
The first one is obviously better; you can pour some lukewarm water over the pump to tighten things up enough for it to start and then add 2-3 quarts of clean engine oil to the tank with every fill-up to increase the viscosity of the fuel and prolong the inevitable. Start saving up for a pump & injectors, or to have the old ones rebuilt, when this first happens to you!
In the second case, when you notice that you have to give it more fuel than normal to climb a hill or maintain speed, start saving for a pump & injectors, or to have the old ones rebuilt. Continuing to drive it can be risky, since you don't know when it'll crap out on you. Most likely it won't be in a place that's either convenient to do the work or inexpensive to get the truck to a place to do the work.
The first one is obviously better; you can pour some lukewarm water over the pump to tighten things up enough for it to start and then add 2-3 quarts of clean engine oil to the tank with every fill-up to increase the viscosity of the fuel and prolong the inevitable. Start saving up for a pump & injectors, or to have the old ones rebuilt, when this first happens to you!
In the second case, when you notice that you have to give it more fuel than normal to climb a hill or maintain speed, start saving for a pump & injectors, or to have the old ones rebuilt. Continuing to drive it can be risky, since you don't know when it'll crap out on you. Most likely it won't be in a place that's either convenient to do the work or inexpensive to get the truck to a place to do the work.
