1975 Datsun 280z FSM - Spooled up Racing

Engine Electrical System
TRANSISTOR IGNITION UNIT
CONTENTS
DESCRIPTION
TRANSISTOR IGNITION UNIT
SPARK TIMING CONTROL SYSTEM
REMOVAL AND INSTALLATION
INSPECTION
1. POWER SUPPLY WIRING
AND BATTERY CHECK
2. CONTINUITY CHECK OF
PRIMARY CIRCUIT
EE-32
EE-32
EE-32
EE-33
EE-33
EE-33
EE-34
RETARDED SIDE PICK-UP COIL
CONTINUITY CHECK
ADVANCED SIDE PICK-UP COIL
CONTINUITY CHECK
5. PICK-UP COIL POWER
SINGLE PULSE CHECK
TRANSISTOR IGNITION UNIT
CHECK
EE-34
EE-34
EE-34
EE-37
DESCRIPTION
TRANSISTOR IGNITION
UNIT
The transistor ignition unit provides
the following functions:
1. It makes and breaks the electric
current in the primary circuit of the
ignition coil.
2. The duty control circuit sets the
rate of make and break within one
cycle, i.e., this maintains good ignition
characteristics of engine from low
speed to high speed and is equal to
the dwell angle in the conventional
breaker type distributor.
3. A preventive circuit against locking
is provided. This cuts off the
primary electric current in the ignition
coil after a fixed (within 10 seconds)
even when the ignition switch is turned
on with the engine not running.
4. On Non-California models, a dual
pick-up coil distributor is used. Tow
signals with phase difference are
generated and transmitted to the transistor
ignition unit from the distributor.
The transistor ignition unit
receives two signals, advanced or
retarded, and has the circuit to select
either of them with the advance control
relay. The transistor ignition unit
used together with the single pick-up
coil distributor is basically the same as
the transistor ignition unit used with
the dual pick-up coil distributor, except
the advance circuit.
Each component part of this unit is
highly reliable, however, should any
part be found faulty, the entire assembly
must be replaced.
SPARK TIMING
CONTROL SYSTEM
When the engine coolant is at low
temperatures, electric current flows
through the advance control relay and
its contact points are opened.
Thus the advance circuit of the
transistor ignition unit operates. When
the engine coolant temperature rises,
current will not flow through the relay
and its contact points are closed.
Thus the retarded circuit of transistor
ignition unit operates.
EE-32