The crankshaft position sensor (CKP) on a 1994 Oldsmobile Achieva with the Quad 4 2.3L engine is located on the
passenger side of the engine block,
near the rear of the engine,
usually quite close to the bellhousing that connects the engine to the transmission. It's often a fairly small sensor with a single wire connector.
Because its exact location can vary slightly depending on specific engine variations and modifications, visually inspecting the area described above is necessary to pinpoint it accurately. A repair manual for your specific year and model would provide the most accurate visual aid.