PROM - Stalls, Long Cranks/Idle/Decel Surge

Group Ref.: Engine Fuel & Emission

Bulletin No.: 336506

Date: October, 1993

SUBJECT:
ENGINE STALL, LONG CRANKS/IDLE/DECEL SURGE
(DIAGNOSE/REPLACE PROM)

MODELS:
1990-93 BUICK REGAL, CHEVROLET BERETTA, CAVALIER, CORSICA, AND LUMINA, OLDSMOBILE CUTLASS, PONTIAC GRAND PRIX AND SUNBIRD WITH 3.1L/3.4L ENGINE (RPO LHO, L01)

This bulletin cancels and supersedes Corporate Bulletin 236512R. Previous divisional publication numbers were:

GM of Canada 92-631-106

Oldsmobile 92-T-138

Pontiac 92-6-60A

Condition:
Some owners of 1990-93 J, L and W cars with the 3.1L engine may experience engine stalling, cold start stall and back-up stalls. Some owners of 1991-93 "W" cars with a 3.4L DOHC engine may experience a slight surge on an extended closed throttle decel when equipped with an automatic transmission; and some owners of 1991-92 W-cars with a 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):

Part Availability:

Parts are expected to be available from GMSPO on 9/13/93.

Warranty Information:

Labor Operation: T-0500

Labor Time: 0.8 Hr.