VW Diesel Dial Gauge Instructions
Step One: Put the Engine at Top Dead Center. You should already have found the timing mark on the flywheel.
Remove the bolt in the middle of the back of the pump.
Screw the timing gauge and adapter in the back of the pump in the same bolt hole.
Starting with the engine at top dead center, rotate the engine backwards until the gauge stops moving. The gauge should be going down, because the rotor inside the pump should be moving towards the front of the pump. The rotor (and gauge) will stop moving when the rollers on the camplate inside the pump has hit a flat spot, stopping the rotor. That's why if you go a little too far, it's OK.
"0" the gauge when the gauge stops moving.
Rotate the engine forwards until you reach top dead center. The rotor should be moving towards the back of the pump, so the gauge should be going up. When you reach Top Dead Center, the gauge should read about.036" - .040" or about .90mm - 1.00mm. It problably isn't right now.
To adjust the timing measurementof the pump, loosen the bolts holding the pump and rock the pump forwards or backwards to get the desired reading on the gauge.