For 1990-2009 cars

# ROUGH IDLE / SURGE HOT INSTALL CANISTER VENT HARNESS

#### VEHICLES AFFECTED: 1988 F-CAR FIREBIRD ONLY W/5.0L AND 5.7L ENG.

Some owners of 1988 Firebirds equipped with V8 PFI engines (VIN Codes F and 8) may experience rough idle at high ambients and surge on driveaway following a hot soak or extended idle. This condition may be caused by interaction between the canister vent and the air cleaner inlet. An indicator of this condition is low Block Learn Memory (BLM) and integrator during an extended idle indicating that the ECM is lowering the base pulse width (injector on time) to compensate for an external source of fuel vapors.

This condition may be addressed by installation of a canister vent harness, P/N 10105257. A clip, P/N 10105274 will also be required to complete the installation.

Parts are currently available from GMSPO.

The harness should be installed as shown in the illustration. The perpendicular line should be connected to the currently open vent port on the canister. The shorter of the two remaining ends should be tucked into the existing hole in the inner fender as shown. The third (longest) end should be pushed through clip, P/N 10105274 until it extends approximately 2.5cm(l inch) beyond the edge of the clip. The clip should then be attached under the existing facia brace bolt as shown. The facia brace bolt can most easily be accessed from underneath the vehicle.

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.