SLUGGISH THROTTLE RESPONSE IN EXTREME COLD WEATHER

MODELS AFFECTED: 1988 SKYLARKS WITH 2.3L ENGINES (VIN D)

Some 1988 Skylarks with the Quad 4, 2.3L (VIN D) engine may experience a condition of sluggish throttle response in extreme cold weather (O degree F/-18 degrees C or below) operation. This may be noticed with the cruise control engaged. However, the service technician may not be able to duplicate the symptom due to a change in the ambient temperature. If, after a thorough diagnosis nothing is found wrong with the vehicle, it may be necessary to install the engine ventilation kit listed below. Engine Ventilation Kit, GMSPO P/N 12339306, contains the following parts:

o Air inlet duct assembly o Crankcase ventilation tube assembly o Fuel vapor harness assembly o Support, engine wiring/vapor o Cap, throttle body port

Parts are currently available from GMSPO.

Figure 1 shows an early and a late 1988 system. Figure 2 shows the 1989 system that is in the kit. The main difference between 1988 and 1989 is that the 1988 has a three port block connector verses a two port block connector on the 1989. Figure 3 shows the support used with the fuel vapor harness assembly. Be sure the vehicle you are working on has a support like this one. Important: this support is used on the late 1988 system.

SERVICE PROCEDURE:

1. Remove the air inlet duct assembly. 2. Remove the vapor harness assembly, be sure to mark the hoses. 3. Inspect the harness support and replace if different than figure 3. 4. Install new vapor harness assembly to the correct ports noted above. 5. Install rubber cap over the exposed port on the throttle body. 6. Install air inlet and crankcase tube assembly. 7. Block drive wheels, set park brake and start the engine to check operation.

WARRANTY INFORMATION:

Labor Operation Number: T4663 Labor Time: 0.3 Hour Trouble Code: 92

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.