To find the potential problem, you'll need to consult your owner's manual for the fuse box diagrams. Look for fuses related to the ignition system, fuel injectors, or the PCM itself (it might be listed as PCM, ECM, or engine control). These fuses are usually in the under-hood fuse box and/or the interior fuse panel. A blown fuse related to the PCM's power supply could cause the engine to not run or run poorly.
Important Note: If you suspect a problem with your PCM, it's best to consult a qualified mechanic. Improperly diagnosing and attempting to repair electrical systems in your car can be dangerous.