I would suggest that you could start looking around the Metering Head for small weaping leaks, especially the electromagnetic Pressure Actuator, small leaks here will let the fuel pressure drop off over night, then there won't be no pressure for it to start. Had this with mine, even though i don't use it, it was when id pull it out the garage it wouldn't start, but soon as it had been running it would, but then come the next day for instance and it wouldn't start.