Range Rover County LWB (LH) V8-4.2L (1993)
The flowchart outlines the correct setting procedure for base idle based upon the symptoms.
Base idle should not be set on a periodic basis. It is not a maintenance item. It is only necessary to check and/or set the base idle whenever:
1.
The MIL is illuminated and a code 48 is recorded on the OBD unit.
2.
The customer complains of an idle stalling problem and no other reason can be found for the problem.
BASE IDLE SHOULD NOT BE ADJUSTED TO ADDRESS ROUGH IDLE COMPLAINTS. BASE IDLE ADJUSTMENTS HAVE NO EFFECT ON
HOT IDLE QUALITY.