F 150 2WD Pickup V6-4.2L VIN 2 (1997)
Ignition Coil: Description and Operation
PURPOSE
The ignition coil:
- Changes low voltage pulses from the PCM to high voltage pulses.
- Sends high voltage pulses to spark plugs through spark plug wires.
OPERATION
When the coil is fired by the PCM, spark is delivered through the matched pair towers to their respective spark plugs. The spark plugs are fired
simultaneously and are paired so that as one fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is
fired the situation is reversed. The next pair of spark plugs fire according to the engine firing order.
CONFIGURATION
Coil packs come in four tower, six tower vertical connector, and six-tower horizontal connector models. Two adjacent coil towers share a common
coil and are called a matched pair.
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For six-tower coil pack (six cylinder) applications the matched pairs are: 1 and 5, 2 and 6, and 3 and 4.
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For dual four-tower coil pack (eight cylinder) applications the matched pairs are: 1 and 6, 3 and 5, 4 and 7, and 2 and 8.
