INTERMITTENT FLICKERING C.E.L. NO CODES STORED

VEHICLES AFFECTED: 1986-90 B, D, F, G, 5.0L

Some 1986-1990 vehicles equipped with 5.0L engine may experience an intermittent flickering check engine light, accompanied by an unstable idle, miss, or rough running engine, with no codes stored. This condition may be caused by a momentary internal open in the distributor pole piece.

To repair this condition use the following procedure:

1. Check ECM power circuits for opens.

2. Check ECM ground circuits for open.

3. 1988-1990 models, go to Step 5.

4. On 1988 and 1987 models perform ECM replacement check, chart C1 in Section 6E1-C1, if passes ECM replacement check, go to Step 5.

5. Replace distributor pole piece. Refer to Section 6D of the appropriate Service Information Manual.

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.