I'm basing this on the fact that the 6.2l's injector pump is the same high-quality
Stanadyne DB2 pump used on the 6.9l and 7.3l IDI's.
One method of IP failure is that clearances get too loose when the pump warms up, If I'm rememebring correctly, if you pour cold water on a hot pump and successfully start the engine, it's definitely the pump, and it's time to replace it. I know that, normally, pouring cold water on a hot pump will ruin it, but if the tolerances are already worn to the point it won't start, you can't ruin it any more than it already is.
Hopefully someone more knowledgable on the GM "diesels" will reply with a more for-sure answer, but that's my $.02...
Good luck!!
p.s. Why not put a Cummins in the Suburban?
