1999 Chevrolet Suburban K2500 Diesel random engine shuts down while driving


#1

After the vehicle sat for 6 months while I couldn’t drive, I started having unexpected engine shutdowns. The dealer has replaced the diesel fuel filter, the inline fuel lift pump and put water eliminator additive into the fuel. Now they say it could be the fuel injection pump, or it needs a new fuel tank. Nothing comes up on the electronic diagnostics. It has been in twice between previous times when the filter was replace and the lift pump was replaced and they said they couldn’t find anything wrong. It was towed home last night. It started right up this morning. The tow truck drive says maybe it is that faulty GM ignition switch. I always keep the fuel tank between 1/2 and full. What could be causing it to go from running great to now replacing any part in the fuel delivery system?
It is so random I can’t get it to mess up at the dealer, but now it is starting to strand me.
I can’t afford to throw money at a problem the dealer can’t definitively put a finger on the problem.