SERVICE MANUAL REVISION MINIMUM IDLE SPEED ADJUSTMENT

MINIMUM IDLE SPEED ADJUSTMENT - SERVICE MANUAL REVISION

VEHICLES AFFECTED: 1988 "J" WITH 2.8L LB6 ----------------- (VIN W) ENGINES

Due to Program changes in the E.C.M. to accommodate the Speed Density System the "Minimum Idle Speed Adjustment" procedure in the 1988 Service Manual "Section 6E3-C2" has been revised. The revised procedure is as follows:

THROTTLE PLATE STOP SCREW (MINIMUM AIR RATE) ADJUSTMENT PROCEDURE

1. Remove throttle plate stop screw plug. 2. Back stop screw out until an air gap between the screw and the throttle lever can be seen by looking downward from above the throttle body. 3. Turn the stop screw in until it just contacts the throttle lever. 4. Turn the stop screw 1 1/2 turns further.

NOTE: If IAC valve counts are still out of acceptable range after idle has been allowed to stabilize, the adjustment may be tailored as follows: More throttle plate opening = lower IAC valve counts. Less throttle plate opening = higher IAC valve counts. If necessary to change adjustment more than one half turn either way, other causes of incorrect idle speed should be investigated as previously mentioned.

5. Adjust TPS per Section "6E3-C1".

The 1988 Cavalier Final Edition Manual will indicate this procedure.

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.