INCREASED IDLE RPM AFTER START UP

ENGINE STALL ONLY AFTER A COLD START OR IDLE SURGE MAY SET CODE 35 NEW SERVICE MEM-CAL

This Bulletin has been revised to include a stall condition and title change and to add repair procedure

VEHICLES AFFECTED: 1988 CAVALIERS, W/2.8L MPFI ENGINE ----------------- Some customers driving 1988 Chevrolet Cavaliers with a 2.BL MPFI engine (VIN Code W) may comment regarding an engine stall or idle surge, which may set code 35, after a cold start only.

If customer comments are received concerning these conditions a new service MEM-CAL should be installed in the electronic control module. The new MEM- CAL may be obtained from CANSPO by ordering the appropriate part number (reference the chart below):

OLD SERV. TRANSAXLE NEW SERV SCAN PROM P/N TRANSMISSION RATIO MODEL MEM-CAL P/N ID -------- ------------ --------- ----- ----------- ---- 16082357 5 - SPD. MAN. 3.61 ALL 16128934 8981 (ANWC)

16082362 3 - SPD. AUTO. 3.18 ALL EXC. 16128936 8991 WAGON (ANWD)

16075560 3 - SPD. AUTO. 2.84 WAGON 16128936 8991 (ANWD)

NOTE: The following procedure MUST be followed when replacing the MEM-CAL to ---- ensure a proper ECM idle learned value.

1. Disconnect the battery negative terminal.

2. Replace the MEM-CAL.

3. Restore the battery power and place the air conditioning controls in the off position.

4. Start the engine, apply brake, and shift the transmission to "drive" for automatics, or "neutral" for manuals. Do not load the power steering system.

5. Allow the engine to run for six minutes. If coolant temperature does not reach 80 degrees C (176 degrees F) after six minutes, continue to run the engine until coolant temperature reaches 80 degrees C (176 degrees F).

This procedure will allow the ECM memory to be updated with the correct idle air control valve position.

If the condition is still present after installing the MEM-CAL, refer to Section 6E3-B of the 1988 Service Information Manual.

Use applicable Labor Time and Operation Code.

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.