"If those grounds are fuel system related why wouldn't they cause the relay to not be grounded enough to allow for 12 v to pass through the relay."

The grounds are for the FI, and since the relay needs the coil energized to switch 12V, they could indeed interrupt the voltage. But the point is, the relay contacts are a switch. On or off. 0 volts or 12V, if that's what's available at the terminal 30 (red wire). The "correction" to that is only for the case that your relay was buzzing, not clicking, in which case it would turn that 12V on and off at a rate fast enough to fool your digital meter into thinking it had some voltage between zero and 12V. But that assumes your hearing the relay was hearing it buzz. I assumed you would have told us that in the first place. So, I don't think your ground wire fix was related to the 8V you measured.

No big deal though. Whatever it was, faulty measurement or re-seated contact, as long as the car is running, you may not care. Then again, many of us fix these old beaters up for our kids to drive, and we want to make sure the gremlins are all worked out before getting that rescue call. Just trying to help with that.
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Art Benstein near Baltimore

Behind every great man is a woman rolling her eyes.