Fuel System - Hard Start/Rough Idle/Misfire
TSB SB05-02-S001Fuel Injection Cleaning Procedure For 3.5L Direct
Injection Engine
SEPTEMBER 19, 2005
Affected Vehicles
2003-2004 Isuzu Axiom and Rodeo with 3.5L DI Engine
Service Information
Condition:
Some owners may comment on drivability 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 an incorrect air fuel ratio. This may trigger either the MIL to light up or the engine to develop various drivability 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.
^ 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 Cleaning Procedure
NOTE:
^ GM Top-Engine Cleaner P/N 8-12346-535-0 is the only injector-cleaning agent recommended. DO NOT USE OTHER CLEANING AGENTS, AS THEY MAY CONTAIN METHANOL THAT CAN DAMAGE FUEL SYSTEM COMPONENTS. Under NO circumstances should the GM Top-Engine Cleaner P/N 8-12346-535-0) be added to the vehicle fuel tank, as it may damage the fuel pump and other system components.
^ Do not exceed a 10% cleaning solution concentration. Higher concentrations may damage fuel system components. Testing has demonstrated that exceeding the 10% cleaning solution concentration does not improve the effectiveness of this procedure.
^ During this procedure, you will need a total of 960 ml (32.4 oz) of cleaning solution (10% GM Top-Engine Cleaner P/N 8-12346-535-0 / 90% Regular Unleaded Gasoline). That is two tanks of solution for the J 35800-A, Fuel Injector Cleaner Tank. Other brands of tools may have a different capacity and would therefore require more or less tanks to complete the procedure. You must use all 960 ml (32.4 oz) of solution (10% GM Top-Engine Cleaner PIN 8-12346-5354) / 90% Regular Unleaded Gasoline) to insure complete injector cleaning.
1. Empty 2 pre-measured GM Top-Engine Cleaner containers, 24 ml (0.812 oz) each, P/N 8-12346-535-0, into the J 35800-A, Fuel Injector Cleaning Tank and fill the injector-cleaning tank with regular unleaded gasoline. If you are using any other brand of tank, you will need a total of 96 ml (3.24 oz) of GM Top-Engine Cleaner P/N 8-12346-535-0 mixed with 864 ml (29.16 oz) of regular unleaded gasoline.
2. Electrically disable the low pressure fuel pump by removing the fuel pump relay. Crank Engine over.
3. Remove fuel line from filter under vehicle and install J 47419 Fuel Line Adapter into the fuel line going to the engine. Use a catch can for any fuel that may drain from the fuel line or filter.
4. Connect the J 3580-A, Fuel Injector Cleaning Tank to the J 47419 Fuel Line Adapter.
5. Pressurize the J 35800-A, Fuel Injector Cleaning Tank to 510 kPa (75 psi).
6. Start and idle the engine until it stalls, due to lack of fuel. This should take approximately 15-20 minutes.
7. Refill the J 3580-A, Fuel Injector Cleaning Tank per step 1.
8. Restart and idle the engine until it stalls, due to lack of fuel. This should take approximately 15-20 minutes.
9. Disconnect J 3580-A, Fuel Injector Cleaning Tank from the J 47419 Fuel Line Adapter.
10. Remove the J 47419 and reconnect the fuel filter and fuel line.
11. Reconnect the vehicle fuel pump relay.
12. Start and idle the vehicle for an additional 2 minutes to ensure residual injector cleaner is flushed from the fuel lines.
13. Add one ounce (30 ml) of Fuel System Treatment, P/N 8-1234-104-0 to the vehicle fuel tank for each gallon (3.78 L) of gasoline estimated to be in the fuel tank. Instruct the customer to add the remainder of the bottle of Fuel System Treatment to the vehicle fuel tank at the next fill-up.
14. Advise customer to change brands of fuel and to add Isuzu Fuel System Treatment every 3000 miles (4800 km). Regular use of Isuzu Fuel System Treatment should keep the customer from having to repeat the injector cleaning procedure.
15. Clear DTC.
16. Road test the vehicle to verify that the customer concern has been corrected.
Parts Information
Warranty Claim Information
Use the labor operation shown.
Disclaimer