Ascender 4WD L6-4.2L (2003)
Fuel Injector: Customer Interest
Fuel System - Multiple Driveability Symptoms
TSB SBO4-02-S002
Multiple Driveability Symptoms Due To Clogged Fuel Injectors
(Clean Injectors)
ISSUE DATE: FEBRUARY 2004
Affected Vehicles
2003-2004 Ascender (US) models equipped with 4.2L L6 engines.
Service Information
Condition:
Some owners may comment on driveability symptoms on long or hard starts, rough idle and light or intermittent misfire. The malfunction indicator lamp
(MIL) may also light up.
Possible Cause:
Due to various factors, the fuel injectors may become restricted. Extensive testing has demonstrated that fuel related issues are the cause of clogged
injectors. At this point, no specific fuel, fuel constituent, or engine condition has been identified as causing the restriction. The restriction causes the
engine to operate at a lean air fuel ratio. This may trigger either the MIL to light up or the engine to develop various driveability symptoms.
Correction:
Fuel injector restrictions and/or deposits, can be cleaned using the following procedure:
^
Under NO circumstances should this procedure be modified, changed or shortened.
^
The recommended mixture amount of GM Top-Engine Cleaner P/N 8-12346-535-0 has been increased from 5% used in prior procedures to 10%.
This increase was implemented to improve the effectiveness of the injector cleaning procedure. Follow the cleaning procedure carefully to minimize
the risk of fuel system damage. Testing has demonstrated that exceeding the 10% cleaning solution concentration does not improve the effectiveness
of this procedure. GM Top - Engine Cleaner P/N 8-12346-535-0 is the only injector-cleaning agent approved for use with GM manufactured fuel
system components. Other injector cleaners, while effective, may cause damage to plastics, plated metals or bearings. The Manufacturer, GM has
completed extensive laboratory testing of the GM Top - Engine Cleaner PIN 8-12346-535-0, and can assure its compatibility with GM fuel system
components, as long as the cleaning procedure is followed correctly.
^
This bulletin recommends the use of pre-measured containers of GM Top-Engine Cleaner P/N 8-12346-535-0, U.S. USAGE ONLY. Pre-measured
containers eliminate the need to measure the precise amount of GM Top-Engine Cleaner P/N 8-12346-535-0 being added to the J 35800-A, injector
cleaning tool.
Service Procedure
Injector service may consist of the following procedures:
^
Injector Balance Test
^
Injector Cleaning
^
Injector Replacement
Injector Balance Test
The following tools or equivalent, are required:
^
J 35800-A Fuel Injector Cleaner
^
J 37287 Fuel Line Shut-off Adapter
^
J 42964 Fuel Line Shut-off Adapter
^
J 42873 Fuel Line Shut-off Adapter
^
Four pre-measured GM Top-Engine Cleaner Containers, 24 ml (0.812 oz) each, P/N 8-12346-535-0.