Diamante warm start problem

1994 Diamante wagon. On occasion the car would not start when warm. I could bump the ignition, rather than hold it on start, and it would fire up. That stopped working. Car went to mechanic who has so far replaced plugs, cap/rotor, wires, ECM relay and tried a used ECM. Car starts fine when cold and runs fine hot or cold. Seems like it has to sit for at least a few minutes when warm to not start, so, if you turn it off and immediately try to start car it will start. Cranks strong, but there is no sound of any combustion trying to occur. Thanks

Are you able to hear the fuel pump run by turning the car on, but not starting it? If so does it do it in failure mode? If you can replicate the problem stop by a shop when ever you pass and think it will not restart, if it does not restart they should be able to figure out the problem. Let them know you are planning that so they can hop on it as soon as it gets there. Some earlier posts have suggested leaving the ignition in the on position for a bit so the fuel system can pressurize before trying to start.