What's wrong with my '90 Olds Cutlass?

I can't figure out what's wrong with it. We've flushed the engine block, changed the radiator which was in bad shape, changed the radiator hose, changed the thermostat, changed the water pump. When the car runs about 5 miles, it starts shaking and jerking pretty bad and then stalls out. It starts back up and idles fine then but when you go to throw it into any gear it shuts back down again. I thought it might be the transmission but I'm not sure? It's a 1990 Oldsmobile Cutlass Ciera with a 4 cylinder engine.70,000 original miles on it and was sitting outside for a while before I bought it. Anyone know what this could be and how I could fix it?
What's wrong with my '90 Olds Cutlass?
You may have a fuel delivery problem. Change the fuel filter. You didn't say if it was overheating.
What's wrong with my '90 Olds Cutlass?
Could be hundreds of things, none of which can be properly diagnosed over the internet for free. I would take it to a reputable shop and pay the one hours diag fee so a professional can run numerous tests and isolate the problem(s). Otherwise you will just be switching parts out hoping for an inexpensive fix and not accomplishing anything. Could be anything from a clogged filter, low fuel pressure, bad transmission, tune up, numerous sensors, low compression, bad engine,catalytic converter, loss of ignition, bad computer, electrical problem etc....