Hi Derrick
I honestly don’t think that’s the issue mate. The contacts swapping over is due to oil pressure dropping at idle and the relay flipping state. See the table below. I got my last response to you slightly incorrect. The pump will continue to operate if either the oil pressure drops or the alternator stops charging but will cut out if both drop out. So from what you describe it’s doing it’s job fine.
The relay does not control the mixture in anyway. What you are describing sounds like the ECU enriching the fuel mixture because of a bad signal from either the temperature sensor or the AFM. The ECU will enrich the air fuel mixture if the water temperature is below 80 degrees. The ECU will also enrich the mix if the air temperature as measured by the AFM is below 40 degrees. So I would firstly check the connectors are good to the temp sensor and AFM first. Then swap out the temperature sensor next. I have a spare one if you need it.
Also check the contacts on the throttle position switch are opening and closing at full throttle. One set of contact should be closed until the throttle is about a third open then the second contact set should close that should stop the ECU adding enrichment at high revs. The EFI bible shows how to adjust it. (Use the engine revs method as it’s most accurate)
Check the AFM flap is not sticking, push it with your finger to ensure it opens and closes smoothly against the spring and returns to the closed position. If it’s sticking slightly open at idle the engine will run rich.
Finally, if you have a spare ECU, try swapping it over. When you blew you fusible links you may have damaged the ECU. Unlikely but a possibility.
We can have a call on the weekend, Sunday is best if you need.
But that relay is not your problem, it’s the mixture staying rich.