On dash codes

The 54 code means the double photo optic sensor unit inside the distributor is failing. Look at the two wire plugs that come out of the distributor. If they are both tight and you see no damage to the wires, then it probably means that the double photo optic sensor unit inside the distributor is going bad. The cam timing is what synchronizes the injector pulses. It is quite easy to change it out yourself. Rotor is held in place by a screw on its side. You don't need to remove the distributor to change it, and that too would avoid any issue with the position/timing of the distributor.