I have a "fly by wire" 6.5 turbodiesel that had 50-some thousand miles on it when I got it, and the pump HAD BEEN replaced with an updated unit. I have put 125,000 miles on the pickup since I've had it, without ANY pump trouble, so they're not all bad! Have they checked the electric lift pump in the frame rail for proper operation, flow and pressure? Those pumps are known to fail, or have intermittant problems, or the oil pressure switch that turns them on can quit, or get intermittant, also. Problems here will cause all sorts of problems that get blamed on the injection pump. A bad crankshaft postion sensor in the front engine cover, or even a worn timing chain, or bad crankshaft vibration dampner can cause the computer controlled pump to do all sorts of weird things. In my area, generally the GM dealers apparently don't mess with the diesel fuel system, but rather, "farm it out" to the authorized Stanadyne shops. (They send the whole vehicle over there). Maybe you could get this thing settled, even if you had to pay for the visit yourself, by going to an authorized Stanadyne dealer. Yes, these things have caused some problems, but I suspect someone is overlooking something on your truck.
|