Signs and Symptoms of a Defective Crank Position Sensor

by Jonathan Lister

The crankshaft position sensor is a component in modern automobiles that records the position of the engine's crank. The sensor also reads basic timing signals for fuel injectors and ignition systems. When this component malfunctions, its symptoms can affect everything, from engine operation to fuel management. According to AA1 Car's website, a crankshaft position sensor requires replacement when it malfunctions and cannot be repaired.

No Engine Spark

A defective crank position sensor may affect the ignition timing of your vehicle. This can result in no voltage being sent to the spark plugs which creates a no-start condition. If the problem is affecting all of the engine's cylinders, the problem is more likely caused by a faulty crank position sensor. If only one or two cylinders are affected, the problem may be an ignition coil.

Fuel Injectors Not Functioning

The crank position sensor also manages fuel injector function in vehicles with distributorless ignition systems. A failing crank position sensor may send inaccurate information to the fuel injectors, resulting in lean or rich fuel mixtures which can create excessive emissions, cause hesitation while accelerating and engine stalling when idling. A failed crank position sensor may not trigger fuel injectors at all which will result in a no-start condition for the vehicle.

Engine Timing Issues

The firing order of cylinders is controlled by the information sent by the crank position sensor. When this component is malfunctioning, the confusion it causes in the firing order may produce hard starting conditions and engine misfires. A hard start is a condition where the engine struggles to turn over. The loud bangs associated with engine misfires can occur at any time, though they may happen more often when the vehicle is accelerating or under strain, such as when towing.

About the Author

Jonathan Lister has been a writer and content marketer since 2003. His latest book publication, "Bullet, a Demos City Novel" is forthcoming from J Taylor Publishing in June 2014. He holds a Bachelor of Arts in English from Shippensburg University and a Master of Fine Arts in writing and poetics from Naropa University.

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