Engine - Stalling, Cold Start Stall, Surge on Decel
NUMBER: 93-T-90CORP.REF.NO: 336506
DATE: September 1993
SECTION: 6E3
SUBJECT:
ENGINE STALL, LONG CRANKS/IDLE/DECEL
SURGE - DIAGNOSE/REPLACE PROM
MODELS/YEARS:
1990-93 CUTLASS SUPREME WITH 3.1/3.4L ENGINE (RPO: LHO, LQ1)
This bulletin cancels and supersedes Dealer Technical Bulletin 92-T-138 which should be discarded.
CONDITION:
Some 1990-93 Cutlass Supreme models with the 3.1L engine may exhibit engine stalling, cold start stall and back-up stalls. Some 1990-93 Cutlass Supreme models with the 3.4L DOHC engine may exhibit a slight surge on an extended closed throttle decel when equipped with an automatic transmission; and some 1990-93 Cutlass Supreme models with the 3.4L DOHC engine and manual transmission may experience cold/hot stalls, diagnostic trouble code 32 at high altitude, open loop drive-away sags and/or hesitation.
CAUSE:
Low volatility/high driveability index fuels now sold in the market place and engine variability conditions.
CORRECTION:
If any of the subject conditions are experienced, they may be corrected by engine calibrations now available to improve engine operational stability and cold (open loop) driveability.
Following procedure listed below:
1. Perform diagnostics, per Section 6E of the Service Manual. Make any adjustments, as required, or replace any defective parts associated with the causes described.
2. If no cause for the stalling is found (using normal diagnostics) and the conditions still exist, then replace the PROM with one from the table (using Service Manual procedures):
1990-93 3.1L Driveability Calibration
1991-93 3.4L Driveablilty Calibration Summary
PART AVAILABILITY: Parts are currently available from GMSPO.
WARRANTY INFORMATION:
Labor Operation: T-0500
Labor Time: 0.8 Hr.