Engine Controls - Cold Start Stall Chuggle at 35-45 MPH

NUMBER:
91-T-185A

CORP.REF.NO:
106503R

DATE:
August 1992

SECTION:
6E3



SUBJECT
COLD START STALL - CHUGGLE AT 35-45 MPH W/TORQUE CONVERTER. CLUTCH ENGAGED - REPLACE MEM-CAL

MODELS/YEARS
1989-91 EIGHTY EIGHT
1989-90 NINETY EIGHT AND TORONADO W/3800 (VIN C) ENGINE



This bulletin cancels and supersedes 90-T-77 and 91-T-185 which should be discarded.

Some owners of 1989-90 Ninety Eights, Toronado/Trofeo, and 1989-91 Eighty Eight models equipped with the 3800 (VIN C) Engine may exhibit one or both of the conditions below. These two conditions are independent of each other, yet it may be possible for both conditions to exist on one vehicle.

^ Engine does not stay running on initial cold start.
^ Chuggle at 35-45 mph with [1][2]torque converter clutch engaged.

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 Dealer Technical Bulletin 91-T-16 "Recommended fuels for 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 "Engine Does Not Stay Running On Initial Cold Starts" only. See Dealer Technical Bulletin 91-T-139 for MEM-CAL installation.






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.






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.

Note:
Some 1991 Eighty Eights with a 2.84 axle ratio and Federal emissions package had a PROM released that used Scanner ID 5644 but had a broadcast code of AWJD. This should not be confused with 16165829 PROM which uses Scanner ID 5644 for a 2.97 axle ratio. DO NOT rely on the Scanner ID to determine which PROM is in a vehicle. Look at the broadcast code on the PROM to be sure.



PARTS STATEMENT:
All parts listed in this bulletin are currently available from GMSPO.

WARRANTY INFORMATION:
Labor Operations No.:
T0500
Labor Time:
0.7 hour (Replace MEM-CAL) 0.2 hour Add to complete chuggle Diagnostic Flow Chart only.
Trouble Code:
92