Sorry it took so long to get back to you. I had a big project straightening up the basement today. I have a little 62 Austin Healey Sprite and has been making a sprawling mess in the basement. How can such a little car look like so much all disassembled?
Plus my computer has prevented hooking up to this thread. Not really sure why. I had to shut off the avatars, images, well, just about all display options plus reduce posts to 5 per page, but at long last here I am!
So, what you are saying is that the car will start and run with the fuel pump relay removed and "0" volts at socket 1 at the fuel pump relay connector?
Well, that's wierd. Obviously the fuel pump is getting power from somewhere, as is the frequency valve. The warm up compensator too, probably. But from where?
Someone I believe has been messing around with the wiring in this car. The wiring to these items must be disconnected before the fuel pump relay and connected to some other power supply.
Unknown why installing the fuel pump relay will make the engine inoperative. Have you considered leaving the fuel pump relay out, since it runs in this state?
Other possiblities would be that you have misidentified the correct relay or there is a flaw in the tests that have been done.