SPARK PLUG FOULING-FLOODING POOR DRIVEABILITY-INJECTORS

VEHICLES AFFECTED: 1985 'A', 'J' and 'X' Series Vehicles Equipped with 2.8L MFI Engine (VIN Code W) and 1983 'F' Series Vehicles Equipped with 2.8L MFI Engine (VIN Code S)

Customer comments of poor engine starting or a no-start condition could be due to spark plug fouling or flooding which may be caused by improper operation of the cold start valve or by a poor spray pattern from the fuel injector(s). A poor fuel spray pattern can also result in driveability conditions of hesitation, lack of performance, or intake manifold backfires on initial driveaway.

Injectore with a revised pintle and spray pattern have been released for production and service. These injejectors have been installed on all engines with a build date code of 0107 (January 7th) or later.

EXAMPLE:

T 01 07 CAF - -- -- --- Source Month Day Engine Code Code Code Type

This code is stamped on a horizontal machined surface on the block just forward of the intake manifold. Engines built before the 0107 date code contain the injectors which may have the poor spray fuel pattern.

Where it is determined that spark plug fouling is the cause of starting conditions, the proper operation of the cold start valve must first be checked. If the operation of the valve checks satisfactorily, then the injectors should be changed. An injector change may also be required to assist a driveability condition. The revised injector is part of a new kit, P/N 17111297 (six (6) kits required per engine).

In the case of spark plug fouling, the spark plugs should also be changed. Spark plug replacement is probably not required in the case of driveability conditions. Follow service manual procedures for injector replacement. Use the applicable labour operation published in the current Labour Time Guide fiche.

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.