Toyota 3R-B 1969, Repair Manual

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I G N I T I O N S Y S T E M - Description 10-1
D E S C R I P T I O N
Ig n itio n Coil D i s t r i b u to r
F ig . 10-1 Ignition System Wiring D iagram G3138
T h e ignition system produces high-voltage su rges of up-to 20,000 volts, and
d e liv e rs them to the spark plugs in "time" with the engine.
Each high-voltage surge jumps a c r o s s the spark plug gap and ignities the co m ­
pressed air-fuel mixture.
T h e ignition system is composed of the prim ary (lo w -v o lta g e ) circuit and the
secondary (high-voltage) circuit, and the w iring diagram is as shown in the
above illustration.
T h e prim ary circuit consists of the battery , distributor b r e a k e r points , cond enser
and the ignition coil prim ary windings.
T h e secondary circuit consists of the ignition coil secondary windings, distributor
cap, ro tor, high-tension w irings and the spark plugs.
When the b r e a k e r points a r e closed, the prim ary current flow s from the battery
through the ignition switch to the prim ary windings in the coil, then to ground
through the closed b r e a k e r points.
When the b r e a k e r points open, the magnetic field built up in the ignition coil p r i ­
mary windings moves through the secondary windings of the coil producing high
voltage su rge.
T h e high voltage su rge is produced each time the b r e a k e r points open. T h e
high voltage flows through the coil high tension wiring to the distributor cap
w h e re the ro tor distributes it to one of the spark plug wiring in the distributor
c a p .