ENGINE SURGE ON DECELERATION INSTALL NEW PROM PACKAGE

SUBJECT: ENGINE SURGE ON DECELERATION

MODEL and YEAR: 1990-91 CORSICA, BERETTA AND CAVALIER WITH 2.2L ENGINE AND MANUAL TRANSMISSION

CONDITION

Some owners of 1991-90 "J" and "L" cars with the 2.2L LM3 engine (VIN Code G), and a manual transmission may comment of an engine surge during deceleration.

CAUSE

Spark is advanced in order to control possible engine pop-backs. This spark allows the engine to surge on deceleration.

CORRECTION

Install a new prom package from the table below:

CAR ENG. TRAN EMISSION PROM PKG BROADCAST SCANNER BODY TYPE TYPE TYPE P/N CODE I.D. ---- ---- ---- -------- -------- --------- -------- J 2.2L MAN FEDERAL 16180513 BBYS 0561 J 2.2L MAN CALIF. 16180515 BBYT 0571 L 2.2L MAN FEDERAL 16180510 BBYP 0541 L 2.2L MAN CALIF. 16180512 BBYR 0551

Parts are currently available from GMSPO.

Labor Operation Number: T0500 Labor Time: 0.4 Hour "J" Car 0.5 Hour "L" Car

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.