The CPS (Crank position sensor): Taken from Wikipedia
A crank sensor is an electronic device used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a timing mark on the engine.
The crank sensor can be used in combination with a similar camshaft position sensor to monitor the relationship between the pistons and valves in the engine, which is particularly important in engines with variable valve timing. This method is also used to "synchronise" a four stroke engine upon starting, allowing the management system to know when to inject the fuel. It is also commonly used as the primary source for the measurement of engine speed in revolutions per minute.
Common mounting locations include the main crank pulley, the flywheel, the camshaft or on the crankshaft itself. This sensor is the most important sensor in modern day engines. When it fails, there is a chance the engine will not start, or cut out while running
Most likely your problem. Look it up online, you'll find a lot of info regarding these sensors
