Service manual

G420F(FE) Service Manual Chapter 4. Engine Electrical System 122
Inspection of Ignition Timing
1. Inspection condition
Coolant temperature : 80-90°C
(At normal temperature)
Lamp and all accessories : OFF
Transmission : In neutral position
Parking brake : ON
2. Inspection
1) Connect the timing light.
2) After inserting the clip backward the connector,
connect the tachometer with the special tool
(09273-24000)
CAUTION
Take care not to disconnect the connector.
3) Measure RPM.
RPM
Low Idle 750 ± 15 rpm
NOTE: If RPM is not normal, it is impossible to
measure the proper ignition timing, so measure it at
a normal RPM.
4) Inspect the standard ignition timing.
BTDC 5˚ ± 5˚
5) If ignition timing is out of the standard, inspect
sensors concerned with ignition timing.
CAUTION
Because ignition timing is fixed by set data
value in ECU, it is impossible to control on
purpose.
Fisrt, check that sensors send output properly to
help determine ignition timing control.
NOTE: Affective ECU input to lgnition timing control
Coolant temperature sensor
Oxygen sensor
MAP sensor(Engine load)
Crankshaft position sensor
Throttle position sensor
Intake Air Temperature sensor
6) Check that actual ignition timing is changed
with engine RPM increased.
Inspection of Ignition Coil Drivers
(Power TR)
Four Power Transistors are used for G420F(E)
engine. Its function is ignition coil driver, and it is
located near to SECM.
Location of Components
(1) Power TRs (2) SECM