Hit with a rubber mallet between the camshaft sprocket and the high pressure fuel pump gear.
Loosen the spring of the VW210 control device by turning.
Install the VW 210 test device between the camshaft toothed pulley and the high-pressure fuel pump gear so that the toothed belt runs between the runners and the measuring probe of the device.
Tighten the spring of the device with the handle to the value on the scale 12-13. On the side of the measuring probe of the control device protrudes a steel tongue, on which a white horizontal line is applied. In this position, this horizontal line should be covered by the edge of the control device. If this is not the case, the tension of the toothed belt should be adjusted.
Adjustment
Install the control device.
By turning the handle to the right, tighten the control spring to the value on the instrument scale of 12-13.
Check the tension roller until the white horizontal line on the steel tongue matches the edge of the housing.
Note: This requires an impact wrench (for example MATRA-V 159 or HAZET 2587).
Install the upper timing belt cover.
Check the moment the high pressure fuel pump starts supplying fuel.
Attention: In the absence of adjustment and control equipment (in case of an accident on the road, abroad) you can also adjust the tension of the toothed belt temporarily. Namely, you should tighten the toothed belt so that it can be turned with difficulty by 90° with your thumb and forefinger.
Caution: However, the timing belt tension should be adjusted with a tester as soon as possible afterwards. Until then, avoid running the engine at high speeds.