I don't know why you would think just any ECU unit would work but I assure you eBay has none. All discontinued quite a while ago. Applicable part numbers depending on date of manufacture
Linda S
Computer, Engine Control
89661-35430
Computer, Engine Control
Production Date:
08/1989-08/1990
Part Name Code:
89661
Replaced By:
89661-35430-84
89661-35560
Computer, Engine Control
Production Date:
08/1990-08/1991
Part Name Code:
89661
Replaced By:
89661-35560-84
89661-35760
Computer, Engine Control
Production Date:
08/1991-08/1993
Part Name Code:
89661