Campaign - CMFI Unit Cleaning/Replacement

Special Policy 99034A - CMFI Failures in
California Only # 99034A

99034A - Special Policy Adjustment -- Central Multiport
Fuel Injection (CMFI) Failures in California Only (YF5 Emission
Equipped)

Certain 1992, 1993, 1994, 1995 S/T, M/L Trucks

Equipped with 4.3L Engine (RPO L35-VIN Code W) and California
Emission RPO YF5.

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.

Condition

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.

Special Policy Adjustment

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 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.

Vehicles Involved





Involved are certain 1992, 1993, 1994 and 1994 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)
built within the following start of production to end of production VIN breakpoints shown.

Parts Information





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.

Customer Notification








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).

Service Procedure

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 the system be replaced. This repair should be performed at no cost to the customer.

Customer Reimbursement





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

Reimbursement

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:

^ Proof of ownership at the time of repair,

^ Original paid receipt confirming the amount of unreimbursed repair expenses(s), a description of the repair, the date repaired, and the person or entity performing the repair

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.