THE FOLLOWING 1981 COMPUTER COMMAND CONTROL DIAGNOSTIC CHARTS ARE TO BE USED IN PLACE OF THE CHARTS PRINTED IN THE 1981 ADVANCED CHASSIS SERVICE MANUAL. THE REVISIONS INCLUDE UPDATED DIAGNOSTICS AND EFE-EGR CANISTER PURGE SOLENOIDS CHARTS. ALSO INCLUDED IN THIS BULLETIN ARE THE: .1981 CARBURETOR SPECIFICATIONS AND ADJUSTMENTS- 3.8L AND 4.1L .IDLE SPEED CONTROL ADJUSTMENTS- 3.8L AND 4.1L (NOTE: DO NOT USE THE ISC IN AN ATTEMPT TO ADJUST CARBURETOR CURB IDLE SPEED, AS THE IDLE SPEED IS CONTROLLED BY THE ECM) .IDLE LOAD COMPENSATOR ADJUSTMENTS .THROTTLE POSITION SENSOR ADJUSTMENTS .PARK NEUTRAL SWITCH .CHART SHOWING DIVISIONAL ENGINE USAGE .VACUUM HOSE AND ELECTRICAL TERMINAL IDENTIFICATION REFER TO ACTUAL BULLETIN TO VIEW CHARTS.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.