OK guys so I just picked up a 96 2500HD with the 6.5T and automatic for dirt cheap... Previous owner got it like it is so he was useless for more info... When you go to start it the starter engages and just grinds... I replaced the starter and got it to crank for a good 20-30 seconds then went back to the grinding noise... After tinkering with it I noticed that another previous owner hard wired the fuel pump so that's why it didn't fire while cranking... Any help would be appreciated

 

Damaged flywheel/flexplate? Make sure you have a starter bracket or your problems can get much worse

 

Mine was shaking the starter even tho the bolts were tight..broke starter bolt of in block...I got it out and studded block, than made shims that went over studs and through starter where bolt goes..out of a piece of metal tube...Makes the bolt{stud} fit tighter through the starter no issues after that..I don't have a bracket am I missing a part? And im suffering from random stalls and throttle bucking every once in a while...PMD??? Lift pump is weak I know... but that's more for initial fire up if I'm not mistaken? It still works and will spray fuel everywhere out the air bleeder...once in a while I wont hear it in the morning till I crank it a few times....think it engages with oil pressure..95 6.5 turbo Im pretty sure its obd 1 I haven't tried scanning it yet.... Whats the obd1 cutoff date?? I get a cel at just above idle than it goes away..

 

I was having same poor running condition. Check the ops. Mine would start then run poorly. The ops was not sending power to the lift pump. as soon as it would start it would shut off the pump. Soon as I replaced the ops and plug( had a burnt lead) runs like a million bucks. Now I am having this starter issue that just grinds all of a sudden even with a new starter.