In general what are the top 10 reasons for a f150
5.0 not start...engine turns over but no start and
tries or almost start with starter spray but it
I can just think of one with the problem you are having if you spray starter fluid and it tries to start the spark plugs are fouled. Replace spark plugs.
If you have spark and fuel but it still won't run it's time to do a compression test. If all cylinders test low or zero it's jumped timing. HTH. -Jim