1995 Questions for all other cars

1995 Questions for all other cars 6 cyl Four Wheel Drive Automatic

I have a grand cherokee laredo 1995
my car starts fine but after a while it turnoff or while is on the run it makes a loud explosive sound ever since this problem started the car comsumes alot of gasoline to. Other mechanics change the pickup coal but that didnt work they even turned off the alarm of the car thinking it might be electric.