I just finished putting my 89 780 turbo back together(replaced rear main seal, radiator, and during the process removed starter, trans and distributor), and as I try to start it it does one of two things: 1 refuses to start or even try to, battery cable must be disconnected and reconnected before electrical system will work again. 2 makes a terriable sound sort of like misfiring or running the car without an exhaust manifold or something ( I dont know, what does "pinging" actually sound like? ). Is this ignition timing being severely off or is it a transmission noise? when the sound happens, I turn the engine off immediately, because it doesnt sound good, so I havent been able to locate the exact source. Any ideas?