It's never really certain how long the injector pump will last. Many variables here. However, you should get at least 150k and some are still going at 250k +++++ Mine is just fine at 160k (fingers crossed). Does the engine shut off right away? If it doesn't, this can be a sign of a dying injector pump. As for the injectors, when I changed mine for the PODs I noticed that the old ones were pretty well crudded up, the truck did seem to smoke a bit more as the miles racked up. You can send your injectors out to a diesel fuel injection shop to have them cleaned and tested. Don't forget the fuel conditioner. This will help your pump by adding lubricity to the fuel and will also help clean up the injectors a bit. I use the Stanadyne Performance Formula, but there are many different ones out there such as Howe's Diesel Treat, etc. etc. Change your fuel filter and check the air filter.
Could you also state what mods have been done to your engine, trans, etc.
Cheers,
Sean