On a 1991 Ford Ranger 2.3L engine, the crankshaft position sensor (CKP sensor) is typically located on the
passenger side of the engine block, near the
bottom of the engine, and generally
close to the crankshaft pulley. It's often a fairly small sensor with a single wire connector.
However, the *exact* location can vary slightly depending on the specific engine configuration and any aftermarket modifications. A visual inspection with the help of a repair manual or a diagram specific to your year and model is recommended to pinpoint it accurately.