Sorted now, was a wiring issue
Hi there how much parasitic drain have you got. If its more tan about 200 mA you ought to find it, leaving the radio on all night could flatten it, i assume FL6 is fused link....well you could find out what that powers, personally i would check the charging system...voltage across battery static should be about 12.4v cranking about 10 volts and charging, about 2 k revs it should be 13.8 to 14.3 volts across the battery....
It might want a new crank sensor, if its that they tend to cause a lot of initial cranking without starting...suppose it could cause it to cut out, if you change it fit a genuine vauxhall one, or good quality one.....as for fuel pressure its pretty high on one of those several thousand pounds psi...so need OpCom or get it checked somewhere....hope that helps...from Fred in Essex.
Hi there well it might not be a core plug but i have know them to go, does it run out the bottom of the bell housing if there is a drain hole there....they used to have drain holes with a split pin in, in the past....does it use much coolant...can you see any other leaks external under bonnet...but i wouldn't worry about that drain on the battery doesn't sound bad enough to drain the battery....good luck with the OpCom...hop it works out...from Fred.