Car sometimes wont start when warm. When it does, sometimes helped by bump starting, there is no smoke therfore no fuel has been getting through. Has just cut out a couple of times while driving - rev counter dropped to 0 revs although still in gear (electriacl problem?). Took to auto electricians; no fault codes, first thoughts crankshaft sensor or ECU but now thinks could be HP fuel pump. Cars done 127k - worried about a big fuel pump bill. Any thoughts?