For 1990-2009 cars

# PORT FUEL INJECTOR CLEANING ON VEHICLE PROCEDURE

1984 CUTLASS CIERA; 1985 FIRENZA, CALAIS, CUTLASS CIERA & NINETY-EIGHT WITH 2.8L, 3.OL & 3.8L V-6 ENGINES

Whenever a driveability condition is encountered on a MPFI equipped Oldsmobile, obvious items such as a disconnected vacuum hose or disconnected spark plug wire should be checked. Then, prior to any system and/or component diagnosis, the injector cleaning procedure as outlined in this bulletin should be performed.

Various types of injector cleaning equipment are available to clean injectors on the car; however, the following procedure was developed using the Kent-Moore J-35800 Fuel Injection System Cleaner to be available approximately November 11, 1985. Follow the equipment manufacturer's instructions for introducing the solution to the fuel rail.

To clean injectors effectively, use a solution of 95 percent gasoline and 5 percent GM Top Engine Cleaner, part number 1050002 or AC Delco Carburetor Tune Up Conditioner, part number X66-P (16 oz. cleaner and 2 gallons of gasoline). Use 1 1/2 quarts of the solution for adequate injector cleaning.

#### IMPORTANT: DO NOT EXCEED THE 5 PERCENT CONCENTRATION OR 1 1/2 QUARTS OF SOLUTION TO PREVENT POSSIBLE DAMAGE TO THE CAR'S FUEL SYSTEM.

#### NOTICE: DO NOT ADD GM TOP ENGINE CLEANER OR AC DELCO CARBURETOR TUNE UP CONDITIONER TO VEHICLE'S GASOLINE TANK, AS DAMAGE TO FUEL SYSTEM MAY RESULT.

#### SERVICE PROCEDURE:

#### IMPORTANT: The fuel system MUST hold system pressure for this procedure. If the system does not hold pressure, repair as required.

1. Mix 16 ounces of GM Top Engine Cleaner or AC Delco Carburetor Tune Up Conditioner with 2 gallons of clean no-lead gasoline.

2. Put 1 1/2 quarts of this solution into the cleaning equipment container and pressurize to 25 pounds pressure with outlet valve closed.

#### NOTE: DO NOT EXCEED 25 POUNDS PRESSURE.

3. Connect cleaning equipment to fuel rail pressure test port.

4. Cycle ignition switch to energize fuel system prime cycle.

5. Open outlet valve of cleaning equipment.

6. Cycle ignition switch again and observe pressure gage. Pressure will read approximately 40 pounds and hold steady. If pressure drops to 25 pounds, (solution container pressure) repair vehicle fuel system for pressure loss.

7. Disable the car's in-tank fuel pump. On some cars it may be necessary to disconnect the connector at the fuel tank.

8. Start engine and run at approximately 2,000 rpm until the solution is used up and engine stops running (approximately 15 to 20 minutes).

9. Turn ignition switch off, close cleaning equipment outlet valve, disconnect cleaning equipment, install fuel pressure test connector cap, and reconnect car's fuel pump.

10. Start and run engine to verify idle quality and check for leaks.

#### WARRANTY INFORMATION

Trouble Code Labor Operation Labor Hours ------------ --------------- ----------- 78 T4085 .5

If the driveability condition still exists after cleaning the injectors, diagnosis using existing chassis service manual procedures should be performed.

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.