Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la
If it fails: lemon-manuals.org.ua

Or, hide this message: temporarily or permanently

Spark Control

The K4 microcomputer controls the generation and timing of spark pulses. The spark advance and dwell characteristics are determined by: engine speed, throttle position, MAP, coolant temperature, barometric air pressure, air temperature, and vehicle speed.