Equus 3551 - INNOVA Inductive Timing Light (DIS) - Manual (Page 5)

ENGINE TIMING AND TUNE-UPS
Proper ignition timing is critical in order to
achieve peak engine performance and to
ensure maximum fuel economy. An ignition
system timing check is critical during any tune-
up procedure. Your timing light provides a
simple and efficient means of checking your
vehicle's timing. The advance timing light
provides the additional ability to check the
operation of your vehicle's mechanical or
vacuum advance timing controls.
You may also need tools and equipment to
check engine rpm, breaker point dwell (for
conventional ignition systems), or to apply
vacuum to the vacuum advance diaphragm on
the distributor during advance checks. Your
supplier offers a wide range of tools and
equipment necessary to perform these tasks.
With reference to today's "self-tuning" vehicles,
the meaning of the term "tune-up" has changed
significantly. A tune-up consists essentially of
checking engine operation with Original
Equipment Manufacturer's specifications.
Adjustments are made and parts are replaced
ONLY if engine performance is not within
specifications.
ABOUT THE TIMING LIGHT
Your timing light is designed for use on all 12-
volt negative ground vehicles equipped with
conventional breaker point, and electronic
ignition systems or with DIS (distributorless
ignition systems). (DIS - Model 3551 ONLY) Timing Light Controls
General controls for the Timing Light are shown
in Figure 1.
3
GENERAL INFORMATION
For 6-Volt Electrical Systems
■ Requires a separate 12-volt automotive
battery.
Your timing light may be used on vehicles
with 6-volt electrical systems by using the
following connection procedure:
1. Connect the RED battery clip to the
positive (+) terminal of the 12-volt
battery.
2. Connect the BLACK battery clip to
the negative (-) terminal of the 12-volt
battery.
3. Using a length of 18AWG jumper
wire, ground the negative (-) terminal
of the 12-volt battery to a known-good
ground on the vehicle under test.
4. Perform remaining connection and
test procedures as specified in the
appropriate sections of this manual.
NOTE
Some DIS systems are not adjustable.
Consult your vehicle's service manual for
procedures and specifications before at-
tempting to time vehicles with DIS systems.
1
2
3 4
0 5 10
15
20
25
30 35 40 45 50
55
60 TIMING LIGHT A D V A N C E
Fig. 1 Timing Light Controls - General