ummm...Throttle Body Injection - that name only should give you a hint that there shoult be an injectors/injector somewhere in the throttle body.
quick google gave me this page:
Identifying Sensors - 1993 Geo Metro 3 cyl TBI 5 speed - Automotive Message Forums
maybe it gives you something useful (at least many sensor locations) - I dont have TBI motor so I dont want to waste more than 2 minutes there.