I have just bought a disco 3.9i v8 gas converted, all was great but it wouldn't run on petrol, on switchover the pump didn't run I have tested the pump with a 12v source & it works, I have checked the electrics from the fuse box to the pump they are all ok but for reasons unknown the fuel pump relay is not being earthed through the Ecu so will not engage the pump does anyone have any experience of this problem? my thoughts are Ecu probs or is the gas conversion chip sending the wrong info to Ecu? When the disco is running on gas I also have problems with backfire through the intake :doh: I think I might just use the petrol in the tank to burn it out