DELAYED AND HARSH UPSHIFTS REVISED THROTTLE BODY ASSY.. Chevrolet Celebrity 1987

For 1990-2009 cars

# DELAYED AND HARSH UPSHIFTS REVISED THROTTLE BODY ASSY.

#### MODEL AND YEAR: 1987 BERETTA, CAVALIER, CELEBRITY, CORSICA WITH 2.8L MPFI V6 ENGINES AND AUTOMATIC TRANSAXLES

Dealer Service Bulletin 87-57 is being reissued to expand vehicle model involvement and a quick inspection procedure for identifying suspected throttle bodies. All copies of Bulletin 87-57 (Section 7A) dated January, 1987 should be destroyed.

Some early built 1987 vehicles listed above with 2.8L v6 engines (VIN Code W) and THM 125C or 440-T4 automatic transaxles may exhibit delayed and/or harsh upshifts.

After the condition has been verified, inspect the Throttle Valve (TV) cable for proper operation and adjustment. (Follow the T.V. cable adjustment procedures contained in the "Automatic Transaxle Section" of the appropriate Service Information Manual.) If the T.V. system is operating properly and the condition still exists, it may be caused by insufficient travel of the throttle lever on the throttle body assembly.

Inspect the throttle lever for an identification hole in the location shown in the illustration. If the lever has a hole, continue following the diagnosis covered in Automatic Transaxle section of the Service Manual. If the lever does not have a hole in it at the location shown, install a new throttle body with a revised throttle lever. Throttle body service kits are as follows:

Celebrity 17111886

Beretta, Cavalier, corsica 17111882

#### NOTICE: THE SERVICE THROTTLE BODY KIT INCLUDES ONLY THE CORE THROTTLE BODY. IT DOES NOT INCLUDE THE FOLLOWING PARTS, WHICH ARE AVAILABLE SEPARATELY:

- COOLANT COVER AND ATTACHING SCREWS

- IDLE AIR CONTROL VALVE, HOUSING AND ATTACHING SCREWS

- THROTTLE POSITION SENSOR AND ATTACHING SCREWS

THESE ITEMS CAN BE TRANSFERRED FROM THE ORIGINAL THROTTLE BODY ASSEMBLY.

Follow the throttle body removal and installation procedures covered in the "Driveability and Emissions-Port Fuel Injection Section" of the Service Manual. After installing the replacement throttle body, preset the throttle stop screw as follows:

- Back throttle stop screw out until it breaks contact with the throttle lever. lever. Turn screw in to lightly contact lever, then 1 3/ 4 additional turns. Final minimum idle speed adjustment should be performed following the procedure covered in the Service Manual.

- Adjust minimum idle speed to 550 RPM plus or minus 50 RPM

- Adjust TPS to 0.55 volts plus or minus 0.1 volts (0.45 to 0.65 volts)

Use applicable Special Labor Operations Number: T1206

Labor Time: 0.9 Hours

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.