2006 Avensis D4D Refusing to start intermittently

[Avensisvetran]

I recently drove the avensis out heavy rain. I stopped the car and turned off the engine to check directions. It then did not fire when I attempted to restart and I called out the recovery firm. The technician tried to jump start it, recharged the Battery and his computer showed nothing was faulty. He eventually managed to start it by pumping the accelerator hard, His verdict was either a problem with the fuel pump or heater plugs, When travelling home the car behaved perfectly.

Having managed to get the car to a local garage they have replaced a fuel pump sensor which has had no effect.

Has anyone encountered this problem?

Any ideas please?