Electric fuel pump is playing up a bit, car starts no prob every morning but if I drive about five mins and stop for petrol say, car won't start (fuel pump wont prime) if i leave it for three mins or so, fuel pump primes and off we go - has done this a few times now. And then cruising down the motorway last night, car dies and wont start (fuel pump not priming) and then again about three mins later, it fires up!

Car is bog standard except full stainless, dump valve and filter, only other thing I can think of is car has an immobiliser fitted which when armed, wont let fuel pump prime or car turn over?

Any help very much appreciated!!