POOR ENG.PERF.& DRIVEABILITY ADDITION OF NON OEM EQUIPMENT

VEHICLES AFFECTED: 1985 S10/15 And M10/15 Vans With Fuel Injected Engines (RPO LN8 2.5L L4

In an effort to prevent customer dissatisfaction concerning engine perfomance driveability and/or operation of other vehicle electrical systems due to the addition of equipment, the following information is being provided.

The 1985 Throttle Body Injection (TBI) engines are designed to work with the electrical system provided in the vehicle. The addition of any electrical or vacuum operated equipment or accessories not offered as original equipment or as a factory approved option may adversely affect the operation of the fuel injection system and the engine performance. Electrical connections should not be made to any of the engine fuel control electrical wiring for a 12 volt source or ground. Equipment operated by vacuum can also affect engine performance and driveability as this allows unmeasured air to enter the engine, which can affect fuel air mixture ratios.

If the addition of a component affects engine performance, driveability or operation, it is recommended that the customer be advised to disconnect the unit which is creating the condition and refer them to the persons responsible for making such installation.

The addition of any electrical or vacuum operated equipment that results in damage to the engine electronics, or creates driveability problems is not the responsibility of General Motors. Such repair expense is the responsibility of the persons or company making such installation.

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.