Special Policy 99034A - CMFI Failures in California Only

This bulletin is being revised to add an injector cleaning process and to include additional parts and labor information. Please discard Special Policy Bulletin Number 99034, dated September, 1999.

Some owners of 1992, 1993, 1994 and 1995 model year S/T and M/L trucks that are registered in the State of California, equipped with 4.3L engine (RPO L35 and VIN Code W) and California emissions (RPO YF5), may experience a hard start condition, rough running engine, a Service Engine Soon light, misfire, no start, stalls or catalytic converter odor due to failure of the Central Multiport Fuel Injection (CMFI) fuel system, also known as Central Port Injection (CPI). Fuels used in the State of California have been found to interact with the CMFI system to cause failures.

This special policy covers the CMFI failure condition described above for a period of ten (10) years or 100,000 miles (161,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership.

The repairs will be made at no charge to the owner. This special policy applies ONLY to repairs requiring CMFI system servicing and/or injector cleaning of the CMFI system. The customer should not be charged for performing a system check when determining that the CMFI system is not the cause of a customer complaint (labor operation T5530 is provided to submit claims for such system checks). Any additional necessary diagnosis and repairs that are not related to the CMFI condition are NOT covered by this special policy. The customer should be informed that any further service that is not covered by new vehicle warranty will not be covered by this policy.

Involved are certain 1992, 1993, 1994 and 1995 S/T and M/L model vehicles registered in the State of California equipped with 4.3L engine (RPO L35 and VIN Code W), California emissions (RPO YF5) and built within the following start of production to end of production VIN breakpoints:

Additional parts, if required, are to be obtained from General Motors Service Parts Operations (GMSPO). Please refer to your "involved vehicles listing" prior to ordering parts. Normal orders should be placed on a DRO=Daily Replenishment Order. In an emergency, parts should be ordered on a CSO=Customer Special Order.

Customers will be notified of this special policy on their vehicles by General Motors (see copy of typical customer letter included with this bulletin -- actual divisional letter may vary slightly).

System Check

Use strategy-based diagnoses listed in the front of the Driveability and Emissions section of the Service Manual. If the CMFI system is operating properly, inform the customer that their vehicle does not have the condition listed in the owner letter. If poor driveability conditions persist, inform the customer that any further diagnosis and repairs will be at their expense if the vehicle is outside the parameters of the New Vehicle Warranty.

CMFI/CPI Injector Cleaning Procedure

If diagnosis leads to sticking poppet nozzles, use the service procedure from Service Bulletin Number 99-06-01-022 in order to clean the CMFI poppet nozzles on the injector tubes. Please note that the service bulletin term for CMFI is Central Port Injection (CPI), but is referring to the same fuel assembly.

Correction

If normal service manual diagnosis indicates that the CMFI/CPI assembly is the cause of the customer complaint, refer to the appropriate Service Manual to replace the CMFI/CPI fuel assembly.

Notice: During the replacement of the CMFI/CPI unit, the two flexible fuel lines that come in from outside of the manifold and connect up to the CMFI/CPI unit will have to be moved. Care should be exercised in repositioning these lines. On high mileage vehicles (>50,000 miles), these lines may have become brittle. In the process of moving these lines it is possible that a leak may develop at the joint where the nylon line is swaged onto the metal piece, which passes through the manifold wall. After replacing the CMFI/CPI unit and just prior to reinstalling the upper manifold cover, it is advised that they system be leak checked. If a leak is observed at these two joints on either of these two lines, both lines should be replaced. This repair should be performed at no cost to the customer.

For vehicles repaired under warranty, submit a claim with the information indicated below.

CUSTOMERS FROM THE STATE OF CALIFORNIA MUST SUBMIT REQUESTS FOR REIMBURSEMENT DIRECTLY TO CHEVROLET, PONTIAC-GMC OR OLDSMOBILE PER INSTRUCTIONS IN THE OWNER LETTER.

These customer requests for reimbursement are for any previously paid repairs to, or replacement of, the Central Multiport Fuel Injection (CMFI) system, regardless of miles. The requests are to be submitted within two (2) years of the date on which the repair was paid, or within the ninety (90) day reimbursement period, ending December 30, 1999, following the receipt of this letter, whichever is later.

When a customer requests reimbursement, they must provide the following:

If the work was done by someone other than a GM dealership, the amount of reimbursement will generally be limited to the amount that the repair would have cost GM to have it completed by a GM dealership.

Dear<<Division(s)>> Customer:

As the owner of a 1992, 1993, 1994 and 1995 model year S/T or M/L truck that is registered in the State of California, equipped with 4.3L V6 engine and California emissions, your satisfaction with our product is very important to us.

This letter is intended to make you aware that some 1992, 1993, 1994 and 1995 model year S/T and M/L trucks that are registered in the State of California, equipped with 4.3L V6 engine and California emissions, may experience a hard start condition, rough running engine, a Service Engine Soon light, misfire, no start, stalls or catalytic converter odor due to failure of the Central Multiport Fuel Injection (CMFI) system.

To address the above-mentioned condition, General Motors is providing special warranty coverage to owners of applicable vehicles registered in the State of California. If the CMFI system failure condition occurs on your 1992, 1993, 1994 or 1995 S/T or M/L truck within 10 years of the date your vehicle was originally placed in service or 100,000 miles, whichever occurs first, the condition will be repaired for you at no charge. Other conditions that may cause similar or different driveability complaints, or cause a Malfunction Indicator Light illumination, that are not a result of CMFI system failure are NOT covered by this special policy. Any repairs made outside the normal warranty coverage due to other conditions would be your responsibility, if you elect to have your dealer provide the service.

This is not a recall campaign . Do not take your vehicle to your <Division> dealer as a result of this letter unless you believe that your vehicle has the condition as described above.

If you have already paid for some or all of the cost to have the CMFI fuel system repaired or replaced, regardless of miles, you should write to <Divisional specific address> to seek reimbursement. Please provide your original paid receipts or invoices verifying repair, the amount charged, proof of payment, the date of payment of those charges and proof of ownership of the vehicle at the time of the repair. This information must be provided within two (2) years of the date on which you paid for the repair, or within the ninety (90) day reimbursement period, ending December 30, 1999, following the receipt of this letter, whichever is later.

If the work was done by someone other than a GM dealership, the amount of reimbursement will generally be limited to the amount that the repair would have cost GM to have it completed by a GM dealership.

Repairs and adjustments qualifying under this special coverage must be performed by a <Division> dealer. You may want to call the service department at the dealer to find out how long they will need to have your vehicle so that you may schedule the appointment at a time that is convenient for you. This will also allow your dealer to order parts if they are not already in stock. Keep this letter with your other important glovebox literature for future reference.

Should your dealer be unable to schedule a service date within a reasonable amount of time, you should contact the appropriate Customer Assistance/Relations Center at the number listed below:

We are sorry for any inconvenience you may experience; however we have taken this action in the interest of your continued satisfaction with our products.

<<Division(s)>>

General Motors Corporation