Volkswagen Golf/Jetta 2 manual

Ignition timing check (Every 10 000 miles (15 000 km) or 12 months)
Routine maintenance and servicing / Ignition timing check (Every 10 000 miles (15 000 km) or 12 months)


Contact breaker system Note: Accurate ignition timing is only possible using a stroboscopic timing light, although on some models a DC sender unit is located on the top of the gearbox casing and may be used with a special VW tester to give an instant read-out. However, this tester will not normally be available to the home mechanic.

For initial setting-up purposes, the test bulb method can be used but this must always be followed by the stroboscopic timing light method
Test bulb method
1 Remove No. 1 spark plug (crankshaft pulley end) and place a thumb over the aperture.

2 Turn the engine in the normal running direction (clockwise viewed from the crankshaft pulley end) until pressure is felt in No. 1 cylinder, indicating that the piston is commencing its compression stroke. Use a spanner on the crankshaft pulley bolt, or engage top gear and pull the vehicle forwards.

3 Continue turning the engine until the line on the crankshaft pulley is aligned with the pointer on the timing cover. If there are no marks on the timing cover, unscrew and remove the DC sensor or blanking plug from the top of the gearbox and align the timing mark (see Specifications) with the timing pointer (see illustrations).

17.3a Crankshaft pulley mark (A) timing mark (B) and TDC mark (C) (timing
17.3a Crankshaft pulley mark (A) timing mark (B) and TDC mark (C) (timing cover removed) - 1.3 litre

17.3b TDC timing marks - 1.6 and 1.8 litre
17.3b TDC timing marks - 1.6 and 1.8 litre

A Flywheel/driveplate B Crankshaft pulley

17.3c Rotor arm aligned with TDC mark on distributor body  1.6 and 1.8 litre
17.3c Rotor arm aligned with TDC mark on distributor body 1.6 and 1.8 litre

4 Remove the distributor cap and check that the rotor arm is pointing toward the No. 1 HT lead location in the cap.

5 Connect a 12 volt test bulb between the coil LT negative terminal and a suitable earthing point on the engine.

6 Loosen the distributor clamp retaining bolt.

7 Switch on the ignition. If the bulb is already lit, turn the distributor body slightly clockwise until the bulb goes out.

8 Turn the distributor body anti-clockwise until the bulb just lights up, indicating that the points have just opened. Tighten the clamp retaining bolt.

9 Switch off the ignition and remove the test bulb.

10 Refit the distributor cap and No. 1 spark plug and HT lead. Once the engine has been started, check the timing stroboscopically.

Stroboscopic timing light method 11 Run the engine until its normal operating temperature is reached.

12 On 1.05, 1.3 and 1.8 litre fuel injection engines, disconnect and plug the distributor vacuum hose.

13 If there are no timing marks on the timing cover and crankshaft pulley, unscrew and remove the TDC sensor or blanking plug from the top of the gearbox.

14 Connect the timing light in accordance with the manufacturers instructions.

15 Connect a tachometer in accordance with the manufacturers instructions.

16 Start the engine and run it at idling speed.

17 Point the timing light at the timing mark and pointer which should appear to be stationary and aligned. If adjustment is necessary (ie. the marks are not aligned), loosen the clamp retaining bolt and turn the distributor body to correct the ignition timing (see illustration).

17.17 Ignition timing marks
17.17 Ignition timing marks

18 Gradually increase the engine speed while still pointing the timing light at the timing marks. The mark on the flywheel or pulley should appear to move opposite to the direction of rotation, proving that the centrifugal weights are operating correctly. If not, the centrifugal mechanism is faulty and the distributor should be renewed.

19 Accurate checking of the vacuum advance (and retard where fitted) requires the use of a vacuum pump and gauge. However, providing that the diaphragm unit is serviceable, the vacuum hose(s) firmly fitted, and the internal mechanism not seized, the system should work correctly.

20 Switch off the engine, remove the timing light and tachometer, and refit the vacuum hose (where applicable).

Transistorised systems
Note: Accurate ignition timing is only possible using a stroboscopic timing light, although on some models a DC sender unit is located on the top of the gearbox casing and may be used with a special VW tester to give an instant read-out. However, this tester will not normally be available to the home mechanic TCI-H
21 Run the engine until its normal operating temperature is reached.

22 On 1.05, 1.3 and 1.8 fuel injection engines, disconnect and plug the distributor vacuum hose.

23 If there are no timing marks on the timing cover and crankshaft pulley, unscrew and remove the TDC sensor or blanking plug from the top of the gearbox.

24 Connect a timing light in accordance with the manufacturers instructions.

25 Connect a tachometer in accordance with the manufacturers instructions.

26 Start the engine and run it at idling speed.

27 Point the timing light at the timing mark and pointer which should appear to be stationary and aligned. If adjustment is necessary (ie. the marks are not aligned), loosen the clamp retaining bolt and turn the distributor body to correct the ignition timing (see illustration 17.17).

28 Gradually increase the engine speed while still pointing the timing light at the timing marks. The mark on the flywheel or pulley should appear to move opposite to the direction of rotation, proving that the centrifugal weights are operating correctly. If not, the centrifugal mechanism is faulty and the distributor should be renewed.

29 Accurate checking of the vacuum advance (and retard where fitted) requires the use of a vacuum pump and gauge. However, providing that the diaphragm unit is serviceable, the vacuum hose(s) firmly fitted, and the internal mechanism not seized, the system should work correctly.

30 Switch off the engine, remove the timing light and tachometer, and refit the vacuum hose (where applicable).

Digifant
31 Run the engine to normal operating temperature, then switch off the ignition.

32 Connect a stroboscopic timing light to the engine.

33 Run the engine at idle speed.

34 Disconnect the wiring from the temperature sender (see illustration).

17.34 Disconnecting temperature sender wire
17.34 Disconnecting temperature sender wire

35 Increase the engine speed to between 2000 and 2500 rpm, then point the timing light at the aperture over the flywheel. The timing marks should be aligned (see illustration 17.17), but if not, loosen the clamp bolt, turn the distributor as required and retighten the bolt.

36 While checking the ignition timing, the opportunity should be taken to check the temperature and knock sensor controls.

37 With the temperature sender wiring disconnected, increase the engine speed to 2300 rpm and note the exact ignition timing.

Hold the engine speed at 2300 rpm, then reconnect the wiring and check that the ignition timing advances by 30 3 from the previously noted value.

38 If the ignition timing only advances about 20, slacken the knock sensor securing bolt, retighten to 20 Nm (15 Ibf ft) and repeat the test. If there is no difference, check the associated wiring for an open-circuit, or as a last resort, renew the knock sensor.

39 If there is no advance in ignition timing, check the temperature sender wiring for an open-circuit. A fault is indicated in the Digifant control unit if there is no open-circuit.


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