Engine - Cold Start Stall/Chuggle At 35-45 MPH

91pontiac07

Bulletin Number: 91-6-49
Reference Number: 106503R
Publish Date: 8/91


Subject: COLD START STALL-CHUGGLE AT 35-45 MPH W/TORQUE CONVERTER CLUTCH ENGAGED REV. CALIB. MEM-CALS

Models
Affected: 1989-91 BONNEVILLE MODELS W/3800 ENGINE


Some owners of 1989 through 1991 Bonneville models equipped with the 3800 (Code C) Engine may experience one or both of the following conditions:

^ Engine does not stay running on initial cold start.

^ Chuggle at 35-45 mph with torque converter clutch engaged.

The two conditions are independent of each other, yet it may be possible for both conditions to exist on one vehicle.

Follow the information outlined under the individual heading for that condition:

ENGINE DOES NOT STAY RUNNING ON INITIAL COLD START

If the vehicle's basic engine controls and fuel systems are operating properly, it is important for the technician to familiarize themselves with information contained in Service Bulletin Number 91-6-9 "Recommended Fuels For Non-Turbo Port Fuel Injection Engines". If the condition cannot be repaired by changing fuel or using currently published service and diagnostic procedures, it may be necessary to install a revised calibration mem-cal. Install mem-cals listed in Table A for this condition only.





CHUGGLE AT 35-45 MPH WITH TORQUE CONVERTER CLUTCH ENGAGED

Proceed with the diagnostic flow chart to aid in identifying the possible cause of the condition.

Note: The new revised calibration mem-cals may slightly affect fuel economy (usually less than 1 mile). Be sure to advise the vehicle owner of this fact.


ENGINE DOES NOT STAY RUNNING ON INITIAL COLD START AND
CHUGGLE AT 35-45 MPH AND WITH TORQUE CONVERTER CLUTCH ENGAGED

Should owners' comments indicate both conditions exist. Follow steps outlined in both procedures. The two conditions are independent of each other. If it is determined that a new revised calibration mem-cal is necessary to correct both conditions, select mem-cals listed in Table B.

Note: The new revised calibration mem-cals in Table B may affect fuel economy. Be sure to advise the vehicle owner of this fact.

TABLE "A"


SCANNER ID WITH BROADCAST SERVICE
YEAR MODEL AXLE RATIO MEMCAL INSTALLED CODE PART #

1989-91 Bonneville 2.84 5614 AYLA 16165848
NATL/CALIF

1989-91 Bonneville 2.97 5634 AYLC 16165839
NATL/CALIF

1989-91 Bonneville SSE 3.33 5654 AYLF 16165834
NATL/CALIF

TABLE "B"


SCANNER ID WITH BROADCAST SERVICE
YEAR MODEL AXLE RATIO MEMCAL INSTALLED CODE PART #

1989-91 Bonneville 2.84 5624 AYLB 16165843
NATL/CALIF

1989-91 Bonneville 2.97 5644 AYLD 16165829
NATL/CALIF

Parts are currently available from GMSPO.

WARRANTY INFORMATION:

Labor Operations: T0500
Labor Time .7 hr. (Replace mem-cal)
.2 hr. (Add to complete chuggle
Diagnostic Flow Chart only.