2001 Astra 1.4 has an intermittent starting problem.
sometimes it starts and drives fine.then the next time i try to
start it, the engine will crank over but won't start.
other times it will start but only with a dab of the throttle.
had it plugged in but there are no faults stored.
i'm suspicious of the fuel pump or the fuel pump relay?
there are four relays in the box under the bonnet,
two green and two purple.which is the fuel pump one?