If you're sure there is 12 volts and a good ground at the pump, but it still won't work, then it's the pump (or connection in the tank).
Thank you very much for your help. I will change the pump this weekend and let you know the results.
Thank you for your help. I put a new fuel pump in and everything seems to be ok. It has started in the heat of the day for several days now so that must have been the problem.
Thank you so much for your help.
Let me know if you have any more problems.