Right went to start the motor up after 10 months on the garage floor. Yestaday i tried it just turned over and didn't even try to fire.So i checked for fuel and there was none to be found at the fuel rail just a hiss of air when i disconneted the fuel pipe. So i tried powering the fuel pump up with another battery, fuel pump started to pump so let it run for a 20 seconds or so. Jumped in the motor and it started. Changed the fuel relay and tried again started so i thought nice one i have solved it I only let it run for half a min then turned off due to lack of backbox. Went to start her again today with backbox fitted and again won't start. Tried the same as yestaday and that won't even work now.
Put a permanent live feed on the fuel pump and see if that helps...failing that the problem i had was very similar to your symptoms but mine turned out to be a Cut fule pipe which was drawing air in...check all your fuel line/hose connections...failing that fuel filter maybe??