My 1997 GM 6.5 diesel has had its engin light on for 4 yers.  I have had problems the whole time and was told by one garage and then a gm dealer that I need a new injection pump.  I agreed with the dealer and said go ahead since it was under the extended warranty.  They called back and said the mechanic had erassed the codes and therefore they could not get the pump from GM.  Code never came back but shows a "mass air intake leak" which nobody seems to know what it means.  Now the engin starts fine, drive away and the engine cuts out like you turned off the key.  Put in neutral and it starts fine then does it again for about 4 times.  Terrible fuel economy, sometimes smokes like blazzes and then stops on its own.  I need help please  

I am not a pro, but it might be your PMD Go to ssdieselsupply.com, the guy that runs that business knows EVERYTHING about the 6.5L and should be able to get your truck running like new