Camshaft Position (CMP) Sensor
CMP sensor is a Hall Effect magnetic switch. The Hall Effect switch is activated by a single vane, which is driven by the camshaft. The CMP sensor provides cylinder identification information during engine start-up for PCM to initiate correct firing order.
Crankshaft Position (CKP) Sensor
CKP sensor is a Hall Effect magnetic switch. The Hall Effect switch is activated by vanes on the crankshaft damper and pulley assembly. The Profile Ignition Pick-up (PIP) is a crankshaft position signal that is sent to the PCM. The PIP signal generated by the Hall Effect sensor provides base timing and RPM information to the PCM.
The PCM controls fuel injector ON time to meter fuel quantity into intake ports. The PCM receives inputs from engine sensors to compute fuel flow necessary to maintain correct air/fuel ratio throughout entire engine operating range. Injector ON time is the only controlled variable in fuel delivery system.
Each cylinder has a solenoid-operated injector that sprays fuel toward the back of each intake valve. Fuel injector nozzles are solenoid-operated valves, which meter and atomize fuel delivered to engine. Each injector receives battery voltage through an ignition switch circuit. The PCM-controlled ground circuit is used to complete the circuit and energize the injector ON time.
Injector bodies consist of solenoid-actuated pintle and needle valve assembly. Injector flow orifice is fixed and fuel pressure at injector tip is constant. Fuel flow to engine is regulated according to length of time solenoid is energized. This period is known as pulse width. Atomized spray pattern is obtained by shape of pintle.
Sunday, April 5th, 2009 AT 5:38 PM