any suggestions as to what may be wrong greatly appreciated. fuel pump is only working intermitently have replaced the pump and relays but still no joy. everything else ok car still runs on lpg. vehicle in question is a 93 ED

If the car runs on LPG and Petrol, there 'should' be another relay between the ECU and the fuel pump relay that controls the power to the Fuel Pump. In some LPS installs they turn the fuel pump off while running on LPG. This relay may be failing.

Check the output from the ECU and see if it is failing there. Worst case is that the ED ECU needs to be replaced, but I would suggest the issue is between the ECU and the Fuel Pump Relay.

Cheers
BenJ