Isuzu 3LA, Руководство пользователя

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III. Engine Servicing Procedures
U
L-Series Diesel 20
Spill Port Timing
Spill-port timing is a precise method of
measuring the initial injection of fuel by
the pump and the duration of injection. It is
a standard procedure used by Isuzu when
timing Zexel pumps. This procedure is a
very precise method of timing fuel because
it shuts off fuel to the high-pressure
chambers relative to the position of the
piston.
Disconnect the injection pipe from the
nozzle holder.
Remove the nozzle delivery valve holder
from the pump. Reinstall the holder
without the delivery spring and delivery
valve. Pressurize the pump. Then rotate the
engine clockwise until fuel quits flowing
out of the holder. (This is the beginning of
the injection).
NOTE: Remember that the injection
pump uses shims to advance or retard
injection. Thicker retards the timing,
thinner advances it).
Observe the reading on the crank pulley in
relation to the timing marks on the gear
case cover. If this value is out of range,
change the thickness of the shims from
underneath the pump. Each shim varies in
thickness by .1mm (.004”), creating a 1
°
change in timing (thicker=retard,
thinner=advance). The shims are a “crush”
design and must not be reused.
NOTE: Refer to the proper specification
sheet for timing adjustment information.
After spill port is performed, be sure to
reassemble all components and install
correctly for proper operation.