Ok man, you got it right "Circuit Open" relay
Sa-weet! And a point for you! There ya go-
Yes, on the 1st gen MR2s, the OCR is actually mounted to the lower left-hand bracket that mounts the ECU to the rear firewall inside the middle of the back trunk.
As for the operation of the OCR, Power is delivered via the EFI Relay when the key is turned to the ON position and the AM2 Circuit is hot. It will be a Black-Red wire that carries the signal (trigger) power to the relay, a White-Red wire that carryes the main (loading) power to the relay, a Blue wire that directly powers the fuel pump, and a White-Black wire that grounds the signal (trigger) power to Close the gate inside of the relay.
I have never looked into the wiring of what's related to the AFM box, but I would assume that the Air Flow Meter controls the White-Black grounding signal wire, and if the key is ON, then the signal has power, and therefore you've got power headed to the fuel pump as the relay closes (by airflow through the AFM during cranking which grounds the OCR's signal circuit).
As for the clutch start cancel, some people associate that with the OCR, but there is actually a separate relay, the Starter Relay, and the clutch switch at the pedal controls that relay's grounding signal wire before the starter will see any power from the relay.
Regards,
BigMike
