1991 Storm 1.6L Starting and Running Problems

Ok here we go!!!!!!!! I have a 1991 Geo Storm 1.6L 89,000 Miles Here is my problem sometimes the car starts and runs for a while then the engine just stops running sometimes it won't start at all I have to wait then it will start up fine... pretty much everything on the engine has been replaced... Injectors, Timing belt, Plugs, Wires, EGR Valve, PCV Valve, Distributor, Coolant Temp Sensor, Vacuum Lines, Fuel Filter, I'm starting to suspect the fuel pump ..... anybody have any thoughts on this please let me know