1990 Pontiac Transport Engine dies after running 10-15 minu

Hi poppa52 and TY for the donation

My 1990 Transport will run for 10-15 minutes, then die something has to give when it dies immediately do below below and tell me what's missing

The mechanic is throwing parts at it and its costing you this is not the right approach

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it