Using Your Timing Light; Before You Begin; Engine Preparation Before Timing; Timing Light Connection - Innova 3351 Owner's Manual

BEFORE YOU BEGIN

Make a thorough check before starting any test
procedure and fix any known mechanical
problems before performing any test. Loose or
damaged hoses, wiring, or electrical connectors
are often responsible for poor engine performance.
Refer to your vehicle's service manual for
proper connection of vacuum hoses, electrical
wiring, and wiring harness connectors. Check
the following areas:
■
All fluid levels
■
Spark plugs and spark plug wires
■
Air cleaner
■
Vacuum hoses
■
Belts
■
Electrical wiring
■
Electrical connectors
ENGINE PREPARATION BEFORE
TIMING
Always prepare the engine for timing before
performing a timing check. Refer to the Vehicle
Emission Control Label or service manual for
timing procedures and specifications for your
vehicle. The Vehicle Emission Control Label is
located under the hood in the engine
compartment. The label is typically located on
the underside of the hood, on a fender well or
valve cover, or near the hood latch.
As a minimum, make the following preparations
before timing:
1. Locate the timing mark and reference
pointer. The timing mark and pointer are
usually located on the crankshaft pulley or
vibration damper (on the front of the
engine) or on the flywheel (between the
engine and transmission). Refer to Figure 4.
Make sure the timing mark and pointer are
clean and clearly visible. Chalk the marks
if necessary.
2. Make sure all spark plugs are in good
condition and properly gapped.

Using Your Timing Light

3.
If applicable, check and adjust dwell to
manufacturer's specifications.

TIMING LIGHT CONNECTION

To ensure personal safety and reliable
operation of the Timing Light, use the following
procedure to connect the Timing Light:
Always keep hands, timing light, lead
wires and clips away from moving engine
parts and hot surfaces. DO NOT SMOKE.
1.
2.
Fig. 4 Typical Timing Marks
14 BTDC
10
6
0 10 20 30
0 TDC
6 ATDC
20
16
12
8
4
0
BTDC
T
10
0 4 8 12 16
Start and run the engine until it reaches its
normal operating temperature. TURN THE
ENGINE OFF BEFORE CONNECTING
TIMING LIGHT.
WARNING!
Turn the ignition off. DO NOT CONNECT
THE TIMING LIGHT WITH THE ENGINE
RUNNING OR WITH THE IGNITION ON.
Clamp the inductive pickup clip around the
No. 1 spark plug wire. See Figure 5.
ATDC
10
BTDC
5