ENGINE MISS, BACKFIRE, HARD TO START & ROUGH/CHUGGLE

SUBJECT: ENGINE MISS,BACKFIRE, HARD START, ROUGH IDLE OR CHUGGLE (INSTALL NEW IGNITION COILS)

MODELS/YEARS: 1987-90 CUTLASS CALAIS AND CUTLASS SUPREME WITH 2.3L (VIN D AND A) ENGINE

CONDITION:

Some 1987-90 Cutlass Calais or Cutlass Supreme models equipped with 2.3L (VIN Code D or A) may exhibit engine miss, backfire, hard start, rough idle or chuggle. These conditions may be caused by the ignition coil. If diagnosis leads to either ignition coil it will be necessary to replace both. (See illustration)

The new type coils have a revised electrical connection tab that is yellow in color to aid in identification. The internal metal pins were also revised for improved durability. These coils went into May 1990 vehicle production. Following are VIN breakpoints for the vehicles involved.

RPO/VIN CARLINE 1987 1988 1989 1990 EMISSIONS ------- -------- ---- ---- ---- ---- --------- LD2/D Cutlass Calais All All All SOP to LM767173 (NA5) LD2/D Cutlass Supreme SOP to LD400017 (NA5) LD2/D Cutlass Supreme SOP to LD400784 (NB2) LGO/A Cutlass Calais SOP to LM766825 (NA5) LGO/A Cutlass Supreme SOP to LD401389 (NA5)

CORRECTION:

----------- Replace BOTH coils with package P/N 10457062. This package contains two coils. Parts are expected to be available on 11/26/90. Until then normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at the dealer's expense. All other order types will be canceled as incorrectly ordered while the 400 control is in place.

For warranty purposes use Labor Operation Number T4676 at 0.7 hour (includes diagnostic time) and 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.