1995 Pontiac Sunfire stalls out, dies. Now won't start at a

Been having problems with stalling out and quitting for about 6 months. Also RPM gauge would go crazy sometimes at high speed, but car would not quit. But check engine light would either come on or kick off, sometimes when hitting a bump, sometimes not. After driving about 35-40 miles, it cut out before getting home, but didn't stall. Next day wouldn't start, towed to garage. Mechanic checked the coil packs and modulater(good), changed the crank or knock sensor(between motor and transmission), Started up for about 40-50 seconds, died again, and won't start again. Changed ignition switch interupter. No work. Cranks but won't start, still. Changed fuel filter, checked pump, relays. ECM relay clicks when trying to start. Also check engine light DOES NOT come on anymore, all others do. Could it be the ECM/ all grounds look good. Plugs and wires good. Any help is greatly appreciated. C