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 or lemon-manuals.org.ua

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Distributor Advance Unit: Description and Operation


The deceleration spark control system decreases hydrocarbon (HC) emission during vehicle deceleration. Ignition timing is advanced by the solenoid operated vacuum valve on the distributor, changing the vacuum supplied to the valve from carburetor ported vacuum to the intake manifold vacuum.