See Figures 1, 2 and 3
Volvo recommends that the ignition timing be checked every 6000 miles (9662 km) on 1970-74 vehicles, 15,000 miles (24,000 km) on 1975-1983 vehicles, and 30,000 miles (48,000 km) on 1984-89 vehicles. Also, a timing adjustment should always follow a breaker point gap and/or dwell angle adjustment (1970-74 models only), and be made with the engine at operating temperature.
Clean the crankshaft damper and pointer on the water pump housing with a solvent-soaked rag so that the marks can be seen. Connect a timing light according to the manufacturer's instructions. Reinforce the marks on the crankshaft damper and on the pointer with chalk or fluorescent paint to highlight the correct timing position. Disconnect and plug the distributor vacuum line (all models) and also disconnect the hose between the air cleaner and the inlet duct at the duct (electronic fuel injected only). Disconnect and plug the vacuum hose at the EGR valve (1973-74 models only). Disconnect and plug the hose from the AIR pump on 1976-77 models so equipped.
Attach a tachometer to the engine and set the idle speed to specifications. With the engine running, aim the timing light at the pointer and the marks on the damper. If the marks do not coincide, stop the engine, loosen the distributor pinch bolt, and start the engine again. While observing the timing light flashes on the markers, grasp the distributor vacuum regulator and rotate the distributor until the marks do coincide. Stop the engine and tighten the distributor pinch bolt, taking care not to disturb the setting.
Reconnect all disconnected hoses and remove the timing light and tachometer leads from the engine.
See Figures 4, 5 and 6
- Remove the rear timing gear cover and disconnect the cold-start device. Loosen the forward screw on the cold-start device control lever, press the lever back toward the stop.
Do not loosen the screw closest to the timing belt.
- Rotate the engine to align the mark on the injection gear with the mark on the pump bracket. The "0" mark on the flywheel should be centered at the timing mark window and with No. 1 cylinder at top dead center.
- Remove the plug from the rear of the pump and install the Volvo dial indicator adapter No. 5194 or equivalent, with a measuring range of 0-0.1 in. (0-3mm). Set the indicator gauge at approximately 0.08 in. (2mm).
- Rotate the engine slowly counterclockwise until the lowest reading on the dial indicator is observed, then re-set the dial indicator to zero.
- Rotate the engine slowly in the clockwise direction until the "0" mark on the flywheel is centered at the timing mark window. The dial indicator should read within the specified range.
When the engine is turned past the timing mark, turn the engine back a1/4of a turn. Rotate the engine in the clockwise direction until the "0" mark on the flywheel is centered in the timing mark window.
- If the dial indicator setting is outside the specified range, loosen the pump bolts and turn the pump until the dial indicator shows the correct setting. Then re-tighten the pump bolts.
- Crank the engine over by hand two revolutions and re-check the injection pump timing. If it is still out of specifications readjust as necessary.
- Remove the dial indicator and adapter, reinstall the rear plug and rear timing gear cover, then reconnect the cold start device.