Maximum off boost injection volume
This adjustment determines how much fuel is injected when there is no boost. Once boost begins increasing, the boost compensator characteristic tendency described above takes over. By increasing the volume of fuel injected, there is more torque available under no boost conditions with the added bonus that with more fuel, more exhaust energy is available to spin the turbo up quicker.
The adjustment screw is found on top of the boost compensator diaphragm and usually has a dab of yellow inspection paint over it (it may however have flaked off with engine washing

Make a note of its stock position for reference. To adjust, loosen the lock nut and screw the adjustment screw in. Initially, turn it in half a turn and tighten the lock nut.
Now it's a matter of trial and error. Warm the engine up and test the adjustment by looking for a light puff of black smoke as you hit the accelerator from idle. You can repeat the procedure and keep increasing the adjustment half a turn at a time until you do see an increase in smoke.
Try to keep the smoke to a minimum when you do finally find a screw setting that suits your engine.
This will have a noticeable effect in the off idle response and can have the turbo spinning up and boosting right down from 1,000 rpm.
A word of caution however. With all this new-found torque at low boost, don't be tempted to lug it up long hills simply because it now can. Bearings don't like being hammered.
I did this mod to mine 6 or so months ago and jumping into a stock TD now it's noticeable just how different it is.