Cummins 4BT – Lucas CAV DPA/DPS Fuel Injection Pump Adjustment Screws

The idle adjustment screw provides a stop for the lever at low speed. The adjustment screw can be used to increase
idle speed for accessory loading or, if required, to lower the idle speed. The high idle screw is sealed and must be
adjusted by an authorized repair shop, and then resealed.
A – Idle screw
B – High idle screw