I ran out of gas, put 1/2 tank of gas in it. Still won't start. Spray starter fluid in breather starts right up and runs, but when you turn the engine off and try to restart, it won't start back.

It is possible the throttle position sensor reading is askew - as in reading higher than it should which will trigger *clear flood* - the ECM then turns off fuel injector pulse - therefore no fuel is injected upon re-start but will return when the engine actually starts. Highly recommend *hands-on* testing using a professional quality scan tool to view various live sensor data - especially the TPS readings. Good luck.