Is there a camshaft sensor in the 1988 Chevy Celebrity 2.8L?

No, the 1988 Chevy Celebrity 2.8L V6 does not have a camshaft position sensor (CMP sensor) in the way later engines do. These older engines relied on a distributor with a pickup coil inside to provide the crankshaft position signal and timing information to the engine control module (ECM). The distributor's rotor and cap then distribute the high voltage to the spark plugs.