Checking and adjusting the ignition timing (VW Transporter T4)

Checking and adjusting the ignition timing

4 and 5 cylinder engine

A tachometer and stroboscope are required for checking and adjustment.

Caution! Adjust the ignition timing only after installing the ignition distributor if the ignition timing value when checking the idle speed or CO content is outside the required value.

1. Turn off the air conditioner (if any).

2. Warm up the engine to operating temperature. Coolant temperature is about 80°C.

3. Turn off the engine.

4. Connect the tachometer to terminal 1 and terminal 15 of the ignition coil (high voltage transformer).

Attention! The ignition must be off.

5. Connect the stroboscope to the positive and negative terminals of the battery. Connect the capacitive clamp to the high-voltage wire of cylinder 1.

6. Remove the crankcase ventilation hose from the pressure regulating valve and position it so that only clean air enters it.



7. Let the engine idle or run at high speed until the radiator fan turns on. Then leave the engine idle and disconnect the coolant temperature sensor plug (2-pole).

Warning! If the engine stops after disconnecting the plug, connect the plug to the coolant temperature sensor before restarting. Otherwise, the control unit will operate in emergency mode, in which correct testing and adjustment are impossible.

8. Let the engine run at test speed.

9. Direct the strobe light into the inspection hole of the clutch housing.

Warning! There is a risk of injury if the fan is switched on suddenly. Disconnect the plug connection before checking.

10. The ignition is adjusted correctly if, during flashes, the ignition timing mark under the corresponding mark is in place.

11. If the ignition timing is outside the control values, adjust the ignition timing according to the required value.

The original can be found at: www.vwmanual.ru



12. To do this, slightly loosen the locking screw on the distributor and turn the ignition distributor so that the adjustment value coincides with the corresponding mark.

13. Tighten the mounting screw to a torque of 25 Nm.


14. Connect the coolant temperature sensor plug (2-pole) and "give gas" 3 times.

15. Check idle speed adjustment.

16. Disconnect the measuring instruments with the ignition off.

17. At the VW service station, interrogate and erase the recorded fault from the control unit's memory. As a result of disconnecting the coolant temperature sensor plug, the fault "Sensor faulty" is recorded in the memory. The memory entry can also be erased by disconnecting the battery.

The importance of ignition timing

Engine	Engine letter designation	Ignition timing before TDC		Test speed, rpm	Maximum speed, rpm
		Test value	Adjustment value
62 kW/ 84 hp	AAS	4°...8°	6° ±1°	2000...2500	5300
81 kW/ 110 hp	AAF	4°...8°	6° ±1°	2000...2500	5300