does it start ok when cold, no good when hot. ok on gas at all times?
if so it sounds the same as mine was last year, i had bad connection at the air flow sensor, i sprayed the connections with a cleaner and it was fine.
the exact symptons where
started fine when cold and switched to gas no prob, when try to restart the now hot engine it wouldnt have it, had to put foot to the floor to get enough of a fire up to get it onto gas and then it was fine, the problem was hot on petrol. it was like it had no fuel going into engine.
some idiot rippoff mechanic (RCR MOTORS rainham) told me he checked it on his computer, it needed 5 injectors so may as well change them all and he quoted £164 per injector, parts only, £200 labour, if that dont cure it change oxysensors. RCR must stand for rippoff car repairs. and he charged me £40 to read fault codes AND £30 labour??? like an idiot i paid it!
any how it worked out to be nothing but was worrying at the time!