Ignition Timing: Adjustments

***UPDATED BY TSB #G00190, JUNE 8, 1990

NOTE: On this distributorless ignition (DLI) system, ignition coil discharge is bipolar -- one side is negative, the other positive. A timing light designed to meet discharge from the negative terminal only will not light or will only light intermittently at the positive terminal.

This condition is a result of timing light design, not vehicle malfunction. Follow these steps to avoid misdiagnosis:

1. Check that your timing light operates correctly when connected to either the positive or negative side of the DLI system. If it does not, do not use it on this system.
2. When purchasing a new timing light, determine whether or not it can be used on DLI systems.

PREPARATION

Fig. 37 Test Connector:

1. Check engine condition (spark plugs, leaks in hoses, etc.).
2. Turn all electrical loads "OFF."
3. Warm engine to operating temperature.
4. Ground test connector (Green: 1-pin) with a jumper wire.

ADJUSTMENT

Fig. 35 Timing Marks:

1. Connect tachometer and check idle speed. If not correct (750 ± 25 rpm), refer to IDLE SPEED in this section.
2. Connect timing light to high-tension lead of front leading side. Check that mark on pulley (yellow) aligns with indicator pin.
3. Connect timing light to high-tension lead of front trailing side. Check that mark on pulley (red) aligns with indicator pin.

LEADING: 5° ± 1° ATDC (Yellow)

TRAILING: 20° ± 2° ATDC (Red)

Fig. 36 Crank Angle Sensor Adjustment:

4. If adjustment is required, remove blind cap, loosen lock bolt and turn crank angle sensor.
5. Tighten lock bolt to 69 - 95 inlb (7.8 - 10.8 Nm) and install new blind cap.
6. Remove test connector jumper wire.