Engine turns over but will not crank

I would strongly suspect the ignition is breaking down. Spark needs insulation to reach the spark plug, it is lazy and will take the easiest path to ground and not jump across the spark plug. Check the spark plug wires ,remove and inspect the distributor cap remove any signs of moisture with a moisture dispellant (clean cloth and WD40) there should be no oil inside the distributor cap or the distributor seal has failed. An engine needs three basic things to start, mechanical integrity (the engine's components must be in synchronization with each other and the engine must be able to develop compression), the engine must get fuel injected into the cylinders (fuel must be injected into the engine ( there is a computer that takes inputs from many sensors on the engine, interprets these signals and decides when and how much fuel to inject into each cylinder) finally the engine needs spark to ignite the fuel injected into the engine, (the spark is also controlled by the vehicle's computer deciding when the spark arrive at the spark plug). If the components in the engine are not in synchronization due to a broken or "slipped" timing belt or chain the engine will not develop adequate compression to start and run properly. If any engine sensor has failed (crank angle sensor, camshaft position sensor, intake manifold pressure senor/air flow meter, coolant temperature sensor) any of these will cause the engine to fail to start by causing a loss of spark or fuel delivery. All these components need electricity to function, a failed fuse, relay, open or shorted electrical circuit could cause the computer, fuel pump or ignition system not to function. Unfortunately there are too many things that could cause your engine not to start to be able to pin point anything to specifically look for. Check for fuel and spark first.

Mine does that too. It has done it so many times. I wait a day or two then it cranks every time. It does it when water splatters under the vehicle from running through a puddle on the driver side. I'm going to seal around the distributor.