SMU - SEC. 6E3 - DRIVEABILITY AND EMISSIONS CHART C-2B

SUBJECT: SECTION 6E3 - DRIVEABILITY AND EMISSIONS - CHART C-2B SECONDARY INJECTOR TEST REVISED

MODELS: 1990-93 ZR1 CORVETTE WITH 5.7L ENGINE (VIN J - RPO LT5)

THIS BULLETIN REVISES SERVICE MANUAL (ST364-94-2) SECTION 6E3-C2 DRIVEABILITY AND EMISSIONS. CHART C-2B SECONDARY INJECTOR TEST IN THIS BULLETIN REPLACES AND SUPERSEDES CHART C-2B SECONDARY INJECTOR TEST USED IN THE 1990-93 CORVETTE SERVICE MANUALS.

THE DIAGNOSTIC STRATEGY HAS BEEN CHANGED TO DIAGNOSE ONE OR MORE SECONDARY INJECTORS OPERATING WHEN NOT IN FULL POWER MODE. SYMPTOMS OF THIS CONDITION MAY INCLUDE ANY OF THE FOLLOWING:

* INCREASED OIL CONSUMPTION * EXHAUST SMOKE BLUE OR WHITE * ROUGH OR ERRATIC IDLE * MISSES AND RUNS ROUGH AT ALL SPEEDS EXCEPT IN FULL POWER MODE * POOR FUEL ECONOMY * EXCESSIVE EXHAUST EMISSIONS OR ODORS * DTC 45 OR 65 SET * LONG TERM FUEL TRIM VALUES SHIFTED LOW

USE THE REVISED CHART C-2B SECONDARY INJECTOR TEST PROVIDED IN PLACE OF CHART C-2B SECONDARY INJECTOR TEST IN THE 1990-93 CORVETTE SERVICE MANUAL.

FIGURES: 6

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.

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