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by Staff
Automobile ignition systems rely on perfect timing. A simple spark, when delivered at precisely the right moment, can mean the difference between a smoothly running, powerful engine that operates cleanly and an engine that runs rough, lacks power and produces unnecessary emissions. Let's get your motor running.

For an engine to make the best use of the fuel, the spark should occur before the piston reaches the top of what?

  • the intake stroke
  • the compression stroke
  • the exhaust stroke

The speed of the pistons increases as the engine speed increases. This means that the faster the engine goes, the spark has to occur when?

  • earlier
  • later
  • No change is necessary.

What is it called when the spark timing is moved closer to the top of the compression stroke?

  • retarding the spark
  • advancing the spark
  • promoting the spark

According to the article, retarding the timing may also eliminate what?

  • compression
  • knocking
  • ignition

What is the difference between a "hot" spark plug and a "cold" spark plug?

  • the lack of a copper gasket
  • the length of the center electrode
  • the shape of the ceramic tip

The coil is a simple device -- essentially a high-voltage transformer made up of ______ of wire.

  • a single coil
  • two coils
  • three coils

The primary role of the distributor is to distribute high voltage from the ______ to the correct cylinder.

  • spark plug
  • piston
  • coil

Spark plugs use this to isolate the high voltage at the electrode, ensuring that the spark happens at the tip of the electrode and not anywhere else on the plug.

  • a ceramic insert
  • insulated wires
  • a copper gasket

Spark timing is so critical to an engine's performance that most modern cars use a sensor to tell the engine control unit (ECU) what?

  • the exact temperature of the spark plugs
  • the exact position of the pistons
  • the exact location of the coil

In a distributorless ignition system, what component has total control over spark timing?

  • the spark control unit (SCU)
  • the engine control unit (ECU)
  • the coil control unit (CCU)