This question is not for a Miata, but a 1992 Mazda B2200 truck
I am having fuel pump problems, with it working occasionally only. I cut out a panel in the bed to get access to the pump ( EFI ) When I unplug the connector from the pump to the harness, I get 11.85V at the pump wire, but when I re-connect the plug to the pump part, I get no voltage. It simply vanishes.
The pump works when I connect 12V to it and the relay checks out ok.
Any suggestions?