HIGHWAY CHUGGLE AND SPARK KNOCK CONCERNS

HIGHWAY CHUGGLE AND SPARK KNOCK CONCERNS

VEHICLES AFFECTED: 1987 J-CAR W/2.0L OHC L-4 ENGINE IN ALL ----------------- TRANSMISSION APPLICATIONS

Customers comments that identify a highway low-speed chuggle or spark knock concern may be repaired with the following changes.

o Intake Manifold Drop-Tube Kit P/N 10106050. If not previously installed as per P.S.B. 87-620-116

o EGR Valve: Automatic Transmission P/N 17112004 Manual Transmission P/N 17112005

PROM Package:

NEW I. D. NEW Division/Trans. PROM P/N (SCAN TOOL) Broadcast Code -------------- -------- ------------ -------------- Pontiac/Auto. 16129055 9082 ANXF Pontiac/Manual 16129053 9062 ANXC Olds., Buick/Auto. 16129056 9092 ANXH Olds., Buick/Man. 16129057 9072 ANXD

The calibration in this prom will also raise TCC lock-up speed by approximately 12 KPH.

If driveability conditions still continue after the above changes, refer to Service Manual Section 6E2-B for further directions.

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.