i think i've sussed this we'll i say me one of my mates who is clued with his cossies has sussed it it's the fuel return valve on the pump it's buggered so when i leave it for a given amount of time the the fuel is running back into the tank if i prime the fuel pump several times before actually trying to start it it will start no probs.
where can i get a furl return valve from?????
hopefully this may help someone in the future.

cheers for the reply,

Phil