I once had the same experience as EZ. I had spark and fuel, but no start (came out of the blue). After checking the basics, I started to poke around the ECU inputs using a OBDII logger. With the ignition on, I just scrolled through the sensor readings to look for anything weird. Funny enough, the coolant temperature read 0F, when it was an easy 95F outside. The car was choking on fuel. Clearly, the sensor was bad. Bought a new sensor, still 0F. It turns out that the wire was broken inside the connector. I soldered in a new connector and the coolant temp read correctly. Engine started right up. An OBDII cable and laptop are invaluable for solving issues like this. These days you can get OBDII bluetooth adapters for your smart phone. I can't imagine not having an OBDII scanner/logger.

Corbin
'97 GSX dressed like a '95 ESi