Still not starting td5

So i have a 2003 td5 defender that sometimes doesnt start?, the fuel pump just sometimes doesnt seem to kick in and hence the car wont start. i have put in a new fuel pressure regulator as the old one was leaking quite bad but the problem still persists, im not getting a new pump just yet as there are times when it starts fine for days on end... im sure i can hear air leaking or being pushed through the pipes or something near fuel filter, or am i being paranoid??? any suggestions would be greatly appreciated

cheers

Sam

Have you looked at the pipes from the tank to the filter.

i have but cant seem to find anything wrong, it has misfired a couple of times too with MIL lamp coming on for a few seconds? back to garage again to see if its the injector harness.

Check the relay for the pump - it might click, but if the contacts have carbon on them they may fail to make contact. Take the casing off and visually check the condition of the contact points (gently scrape the crap off them if they are crusty.)