EXHAUST ODOR/COLD SHIFT SAG/ COLD HESITATION ON LIGHT ACCEL. GMC Truck GMC Suburban

********************************************************************** CONDITION: SOME OWNERS OF 1993 MODEL YEAR C/K TRUCKS AND G VANS WITH 5.7L (L05) V8 ENGINES (VIN K) MAY COMMENT ON ONE OR ALL OF THE FOLLOWING CONDITIONS:

* EXHAUST ODOR (H2S). * COLD START SAG. * HESITATION/FLAT FEEL ON LIGHT ACCELERATION DURING THE WARM-UP PERIOD ON COLD START.

CAUSE:

AIR FUEL MIXTURE WAS NOT OPTIMALLY CALIBRATED FOR ALL OPERATING CONDITIONS.

CORRECTION:

IF NORMAL DIAGNOSTICS AND SERVICE PROCEDURES DO NOT CORRECT ANY OF THE ABOVE CONDITIONS, A REVISED CALIBRATION MEMCAL SHOULD BE INSTALLED (SEE CHART BELOW).

PART INFORMATION:

1993 L05 (5.7L) WITH M30 (4L60E) TRANSMISSION ONLY

NEW NEW B/C CODE PROM BODY EMISSION NEW PROM (PROM I.D. STYLE SERIES TYPE AXLE KIT # LABEL) (SCAN TOOL) PICKUP C1500 NA5/NA6 GU4(3.08) 16197750 BJJA 7775 PICKUP C2500 NA5/NA6 GU6(3.42) " " "

PICKUP C1500 NA5/NA6 GU6(3.42) 16197754 BJJB 7785 PICKUP C2500 NA5/NA6 GT4(3.73) " " "

PICKUP C1500 NA5/NA6 GT4(3.73) 16197758 BJJC 7795 PICKUP C2500 NA5/NA6 GT5(4.10) " " "

ALL K1500 NA5/NA6 GU6(3.42) 16197761 BJJD 7805 PICKUP K2500 NA5/NA6 GU6(3.42) " " "

SUBURBAN C1500 NA5/NA6 GU6(3.42) 16197764 BJJF 7815 ALL K1500 NA5/NA6 GT4(3.73) " " " PICKUP K2500 NA5/NA6 GT4(3.73) " " "

SUBURBAN C1500 NA5/NA6 GT4(3.73) 16197768 BJJH 7825 ALL K1500 NA5/NA6 GT5(4.10) " " " PICKUP K2500 NA5/NA6 GT5(4.10) " " "

G-VAN G1500 NA5/NA6 GU4(3.08) 16197771 BJJJ 7835 G-VAN G2500 NA5/NA6 GU4(3.08) " " " G-VAN G3500 NA5/NA6 GU5(3.23) " " "

G-VAN G1500 NA5/NA6 GU6(3.42) 16197774 BJJK 7845 G-VAN G2500 NA5/NA6 GU6(3.42) " " "

G-VAN G2500 NA5/NA6 GT4(3.73) 16197778 BJJL 7855

PICKUP C1500 NB2 GU4(3.08) 16197739 BJHX 7745 PICKUP C/K2500 NB2 GU6(3.42) " " " SUB/BLAZER K1500 NB2 GU6(3.42) " " " YUKON K1500 NB2 GU6(3.42) " " "

ALL C1500 NB2 GU6(3.42) 16197743 BJHY 7755 PICKUP C/K2500 NB2 GT4(3.73) " " " SUB/BLAZER K1500 NB2 GT4(3.73) " " " YUKON K1500 NB2 GT4(3.73) " " "

ALL C1500 NB2 GT4(3.73) 16197747 BJHZ 7765 PICKUP C/K2500 NB2 GT5(4.10) " " "

G-VAN G2500 NB2 GU4(3.08) 16197781 BJJM 7865 G-VAN G3500 NB2 GU5(3.23) " " "

G-VAN G2500 NB2 GU6(3.42) 16197784 BJJN 7875

G-VAN G2500 NB2 GT4(3.73) 16197788 BJJP 7885

NA5: FEDERAL EMISSIONS NA6: EMISSION SYSTEM, HIGH ALTITUDE REQUIREMENTS NB2: EMISSION SYSTEM, CALIFORNIA

PARTS ARE EXPECTED TO BE AVAILABLE FROM GMSPO AUGUST 16, 1993.

WARRANTY INFORMATION:

LABOR OPERATION: T0500 LABOR TIME: 0.6 HRS. - C/K TRUCKS 0.5 HRS. - G-VAN

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.