so I have a 95 buick riviera and one day when i put it into reverse it was hesitant but it went and the next day when i put it into reverse it died. it would start but when you put it into gear it would die, so i was told a fuel pump. well I have replaced the fuel filter, fuel pump, fuel pressure regulator, ignition control module, coils, crankshaft position sencor, catilac converter, mass air flow sensor, throttle position sensor and egr valve and now it will start and stay running after it warms up but it still wants to stall in gear it will drive but it has no power its like it wants to stall its still hesitant. i am at wit end with this and clueless also i dont know what else could be wrong.