will not start after already been driven.

Two thoughts. The ignition module could be bad. This needs to be dynamically tested (i.e. tested on a machine that heats it up to operating temperature). You could also have a bad fuel pump or fuel pump relay. Next time it won't start, turn the key (without cranking the engine) and listen for a buzzing for 10-15 seconds from the rear of the vehicle. This is the fuel pump pressurizing the lines. If you don't hear this, it's fuel pump problems.