Here is a tech bulliten on the injectors on your vehicle, the other concern may be a dirty MAF.
TECHNICAL SERVICE BULLETIN Reference Number(s): 03-06-04-030F, Date of Issue: December 10, 2007 Related Ref Number(s): 03-06-04-030, 03-06-04-030A, 03-06-04-030B, 03-06-04-030C, 03-06-04- 030D, 03-06-04-030E, 03-06-04-030F ARTICLE BEGINNING CONDITION Some customers may comment on any of the following various driveability symptoms: Ã Extended Crank Time Ã Hard to Start Ã MIL/SES Illuminated with DTCs Ã Hesitation Ã Lack of Power Ã Surge or Chuggle Ã Rough Idle Ã Light or Intermittent Misfire 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 either trigger the MIL to illuminate or the engine to develop various driveability symptoms. CORRECTION Fuel injector restrictions, deposits can be cleaned on the vehicle using the following procedure. Under NO circumstances should this procedure be modified, changed or shortened. As a long term solution, and to prevent reoccurrence, customers should be encouraged to use Top Tier Detergent Gasoline. Affected Model(s): 2000-2008 GM Passenger Cars and Light Duty Trucks (Including Saturn); 2003-2008 HUMMER H2; 2006-2008 HUMMER H3; 2005-2008 Saab 9-7X; with 2.0L, 2.2L, 2.4L, 2.8L, 3.1L, 3.4L, 3.5L, 3.8L, 3.9L, 4.2L, 4.3L, 4.8L, 5.3L, 6.0L, 6.2L or 8.1L Engine (VINs X, F, D, 4, 5, T, 8, J, E, H, L, 6, K, 1, 2, R, W, S, X, V, T, M, N, U, H, Y, 8, G - RPOs LNF, L61, LN2, L43, LD9, LK5, LG8, LA1, LX5, LX9, LZ4, LZE, L52, L36, L67, L26, LZ9, LZ8, LGD, LL8, LU3, LR4, LM7, LH6, LQ9, LQ4, LS2, L76, L92, L18); and MULTEC 2 Fuel Injectors Supercedes: This bulletin is being revised to update the model year to 2008. Please discard Corporate Bulletin Number 03-06-04-030E (Section 06 - Engine/Propulsion System).
INJECTOR CLEANING PROCEDURE 1. For 4, 5 and 6 cylinder engines, empty two of the 30 ml (1 oz) reservoirs of the GM Upper Engine and Fuel Injector Cleaner container into the J 35800-A - Injector Cleaning Tank then add 420 ml (14 oz) of regular unleaded gasoline. If you are using any other brand of cleaning tank, you will need a total of 60 ml (2 oz) mixed with 420 ml (14 oz) of regular unleaded gasoline. 2. For 8 cylinder engines, empty two of the 30 ml (1 oz) reservoirs of the GM Upper Engine and Fuel Injector Cleaner container into the J 35800-A - Injector Cleaning Tank then add 420 ml (14 oz) of regular unleaded gasoline. If you are using any other brand of cleaning tank, you will need a total of 60 ml (2 oz) of Upper Engine and Fuel Injector Cleaner mixed with 420 ml (14 oz) of regular unleaded gasoline. This procedure will need to be repeated for a second time for an 8 cylinder engine (8 cylinder engines receive 960 ml total fluid - 120 ml (4 oz) of Upper Engine and Fuel Injector Cleaner and 840 ml (28 oz) of gasoline. 3. Be sure to follow all additional instructions provided with the tool. 4. Electrically disable the vehicle fuel pump by either removing the fuel pump fuse or the fuel pump relay and disconnecting the oil pressure switch connector, if equipped. 5. Turn the ignition to the OFF position. 6. Relieve fuel pressure and disconnect the fuel feed and return lines at the fuel rail. Plug the fuel feed and return lines coming off the fuel rail with J 37287, J 42873 or J 42964 as appropriate for the fuel system. 7. Connect the J 35800-A to the vehicle fuel rail. 8. Pressurize the J 35800-A to 510 kPa (75 psi). 9. Start and idle the engine until it stalls, due to lack of fuel. This should take approximately 15-20 minutes. NOTE: GM UPPER ENGINE AND FUEL INJECTOR CLEANER is the only injector cleaning agent recommended. DO NOT USE OTHER CLEANING AGENTS AS THEY MAY CONTAIN METHANOL, WHICH CAN DAMAGE FUEL SYSTEM COMPONENTS. Under NO circumstances should the GM Upper Engine and Fuel Injector Cleaner be added to the vehicle fuel tank. Do not exceed the recommended cleaning solution concentration. Testing has demonstrated that exceeding the recommended cleaning solution concentration does not improve the effectiveness of this procedure. IMPORTANT: Vehicles with less than 160 km (100 mi) on the odometer should not have the injectors cleaned. These vehicles should have any out of specification injectors replaced.10. Turn the ignition to the OFF position. 11. Disconnect the J 35800-A from the fuel rail. 12. Reconnect the vehicle fuel pump relay and oil pressure switch connector, if equipped. 13. Remove the J 37287, J 42873 or J 42964 and reconnect the vehicle fuel feed and return lines. 14. Start and idle the vehicle for an additional two minutes to ensure residual injector cleaner is flushed from the fuel rail and fuel lines. 15. Pour the entire contents of GM Fuel System Treatment Plus (P/N 88861011 [in Canada, P/N 88861012]) into the tank and advise the customer to fill the tank. 16. Review the benefits of using Top Tier Detergent gasoline with the customer and recommend that they add a bottle of GM Fuel System Treatment Plus to the fuel tank at every oil change. Regular use of GM Fuel System Treatment Plus should keep the customer from having to repeat the injector cleaning procedure. 17. Road test the vehicle to verify that the customer concern has been corrected. PARTS INFORMATION Parts Information * Only 1/8 of the cost may be claimed for 4 and 6 cylinder engines and 1/4 of the cost for 8 cylinder engines. WARRANTY INFORMATION (EXCLUDING SAAB U.S. MODELS) For vehicles repaired under warranty, use: Warranty Information (excluding Saab U.S. Models) Part Number Description Qty 88861802 GM Upper Engine and Fuel Injector Cleaner 473 ml (16 oz) Container (U.S.) 1* 88861804 GM Upper Engine and Fuel Injector Cleaner 473 ml Container (Canada) 1 88861011 Fuel System Treatment Plus 591 ml (20 oz) Container (U.S.) 1 88861012 Fuel System Treatment Plus 591 ml Container (Canada) 1 Labor Operation Description Labor Time *J5645 Cleaning Injector: 4 Cylinder Engine 0.8 hr 5 Cylinder Engine 0.7 hr 6 Cylinder Engine 0.7 hr 8 Cylinder Engine 0.9 hr **Add: Diagnostic Time 0.0-0.3 hr * This labor operation number is for bulletin use only. This number will not be published in the Labor Time Guide. **A total diagnostic time equal to the time allowed for cleaning, J5645, may be claimed for performing the injector diagnosis procedure.
Thursday, February 26th, 2009 AT 2:33 PM