HIGH OUTPUT IGNITION COIL HESITATION, SAGS, STUMBLES

1984 & 1985 FIREBIRD WITH LB9 & L69 ENGINES

"Please discard previous bulletin 85-6(Gasoline)-40 due to this revision which makes this information applicable to 1984, also. "

Some 1984 and 1985 Firebirds with high output ignition coils may exhibit driveability problems ranging from hesitations, sags, and stumbles to complete ignition cut-out. These conditions may be caused by a short in the secondary windings of the high output ignition coil caused by extended exposure to high temperatures.

Should any vehicle/engine combination stated above experience the described driveability conditions and normal service procedures (see Service Manual) do not correct the conditions, the following steps are to be taken to prevent future reoccurrences.

1. Replace the high output coil and distributor module with standard output coil and module as listed below:

Model Vehicle Engine Replacement Replacement Years Model RPO Coil Module ----- ----- --- ---- ------

1984/85 Firebird L69 1985473 1976908

1984/85 Firebird LB9 1985473 1976908

2. Remove and regap spark plugs to .035 inch.

3. Check and reset ignition timing to specifications as indicated on the vehicle emissions label.

Anytime a vehicle is modified for an emission change (spark plug gap), a new label is needed. The label should be affixed in a readily visible position in the engine compartment and where possible beside an existing emission control information (tune-up) label and should not be affixed to any equipment that can be easily detached from the vehicle. Refer to the chart for the correct label to be used:

FOR 1984 & 1985

Usage Label Part No. ----- -------------- Firebird With L69 and NA5 14086583

Firebird With L69 and NB2 14086585

Firebird With LB9 and NA5 14086588

Firebird With LB9 and NB2 14086590

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.