How do you adjust engine idle speed on a T4 caravelle 2.5tdi?

To adjust the engine idle speed on a T4 Caravelle 2.5 TDI, locate the idle speed adjustment screw on the injection pump. First, ensure the engine is at operating temperature. Then, with the engine running, turn the screw slightly clockwise to increase the idle speed or counterclockwise to decrease it, checking the RPMs with a tachometer as you adjust. Always ensure the adjustment is within the manufacturer's specified idle speed range for optimal performance.