Doosan G643, Руководство по обслуживанию

Страница: 127 / 260

G643(E) Service Manual Chapter 4. Engine Electrical System 125
4. Start the engine, using the timing light verify the
engine is running at the correct timing, in this case
10° BTDC. If it is not 10° BTDC loosen the
distributor hold down bolt and slightly adjust the
distributor for 10° BTDC using your timing light.
Tighten the distributor hold down bolt.
5. Un-check the Spark Control Lock, it should now
read “Unlocked” as in Figure 42 allowing the
SECM to control spark advance.
6. Enter 0.00 in the Spark Offset, the Warning
message should now read OFF as in Figure 44.
The SECM is in full control of the spark advance
with no offset.
7. Setting the distributor position is now complete.
Figure 44. SECM in Full Control of Spark
Advance
Ignition Timing Adjustment for G643E
Engine
On
G643 engine, crankshaft position was sensed
from the distributor. Adjusting the distributor has a
direct affect on ignition timing - 1 degree of the
distributor rotation would produce a 2 degree
change in spark timing.
G643E engine senses crank position from the crank
position sensor and the target wheel. Rotating the
distributor will not directly affect ignition timing,
except in extreme conditions. When engine is
disturbed and ignition timing is incorrect, inspect the
sensors concerned with ignition timing, at first.
[Figure] Crank Position Sensor of G643E Engine
NOTE: Affective SECM input to ignition timing
control
• Coolant temperature sensor
• Oxygen sensor
• Battery voltage
• MAP sensor (Engine load)
• Crankshaft position sensor
• Throttle position sensor
• Intake Air Temperature sensor
If the distributor is severely misaligned, the rotor will
not properly align with the distributor cap and spark
will misfire or go to the wrong cylinder. When
replace the distributor, install new distributor as
follows;
1. Install distributor shaft into engine, aligning marks
made at time of removal (see, figure). Be sure that
the shaft engages oil pump
2. Secure distributor with clamp
3. Install distributor cap