Please provide more info about what you have done with the car. You or your mechanic should have taken lots of troubleshooting steps PRIOR to replacing the PCM. BTW, PCM's almost never fail.
Fuel pressure: how much psi are you reading?
Spark plug health, type and gaps?
Engine cylinder compression test results for each cylinder in psi?
OBD Scan: any codes?
Edit: maybe someone spiked your gas tank with some kinda crap? Do you have a locking gas cap?