The first suspects are the fuel injection relay and the radio suppression relay (the radio suppression relay supplies power to the injectors). Remove them, remove the caps, inspect the solder joints with a magnifying galss, and re-solder the copper tabs sticking through the printed circuit board.

The second suspect would be the Hall effect sensor in the distributor and the wiring connecting to it. If you crank the engine and the tachometer needle does not bounce, you have a problem with the Hall effect or the wires. Look at the electrical connector at the bottom of the distributor from the left hand side of the car. Is the electrical connector attached to the distributor, or is it hanging from the three wires inside the distributor? If the connector is hanging from the wires, the wires will wear through the insulation and make intermittent contact with the metal housing and the car will not run.

The third suspect would be the power stage (ignition amplifier) which is mounted on the front of the left front fender well. I haven't had a bad one, but I know they do fail and there is info in the 700/900 FAQ on testing them.

The last suspect would be the main fuel pump, but although I have had one fail, it did not decide to work at a later start attempt. It just quit!