Timing Adjustment; Advance Timing Control Checks - Innova 3551 Manual Del Propietário

NOTE
If the Timing Light fails to operate or
operates erratically, refer to TROUBLE-
SHOOTING to determine the most likely
cause of the problem.

TIMING ADJUSTMENT

Refer to your vehicle's service manual for the
proper procedures to adjust engine timing. DO
NOT ATTEMPT TO ADJUST ENGINE TIMING
WITHOUT THE
PROCEDURES OR SPECIFICATIONS.
ADVANCE TIMING CONTROL
CHECKS
The following tests apply to Advance
Timing Light Model 3555 ONLY
Advance and retard timing controls ensure that
ignition occurs at the proper time during the
compression stroke. These controls include:
■
mechanical advance
■
vacuum advance
■
vacuum retard
■
electronic advance
■
electronic retard
■
electronic advance /retard
Depending on make and model, a vehicle may
be equipped with a single timing control device,
or two or more devices may be used in
combination.
NOTE
Advance timing test procedures vary widely
from vehicle to vehicle. The following
paragraphs provide general test procedures
for checking mechanical/ centrifugal advance
and vacuum advance. ALWAYS make sure
initial timing and dwell are correct before
checking advance timing. ALWAYS refer to
the service manual for the vehicle under test
to obtain the proper timing procedures and
specifications. OBSERVE ALL SAFETY
PRECAUTIONS.
Using Your Timing Light
MANUFACTURER'S
Checking Mechanical/Centrifugal Timing
Advance
1. Rotate the Advance Control Knob
counterclockwise to the "0" degree
position.
2. While performing an INITIAL (BASE)
TIMING CHECK as previously described,
slowly increase engine speed to the
manufacturer's
mechanical/centrifugal advance, and
observe the rotating timing mark for
change. The timing mark should appear to
move smoothly, in the opposite direction
of engine rotation, away from the
reference pointer.
NOTE
If timing mark movement is rough or erratic,
the mechanical advance system may be
defective. Service and repair the mechanical
advance system in accordance with the
manufacturer's instructions before continuing.
3. Rotate the Advance Control Knob
clockwise until the rotating timing mark
and the reference pointer realign at the
base or initial timing mark as previously
recorded. Read the degrees of mech-
anical or centrifugal advance on the
Advance Control Knob's calibrated dial.
See Figure 7.
Fig. 7. Advance Control Knob Operation
specified rpm for
7