Engine - Cold Start Stall/Hesitation/Sag/Cold Rough Idle
File In Section: 6E - Engine Fuel & EmissionBulletin No.: 47-65-23A
Date: September, 1995
Subject:
Cold Start Stall/Sag/Hesitation/Cold Rough Idle or Improper Defroster Operation at Moderate Temperatures (Install New PROM)
Models:
1994-95 Buick Century
1994-95 Oldsmobile Cutlass Ciera
with 3100 V6 Engine (VIN M - RPO L82)
This bulletin is being revised to add the 1995 model year, reflect new A/C low pressure values for turning on the A/C compressor clutch, new PROM and [1][2]PCV elbow part numbers. Please discard Corporate Bulletin Number 47-65-23 (Section 6E - Engine Fuel & Emission).
Condition
Some owners may experience a cold start stall, cold tip in hesitation and/or a cold rough idle after extended idling. Additionally, in 40-50°F ambient temperatures some owners may comment of togging on the inside of the front windshield which does not clear with the defroster on.
Correction
The following guidelines should be followed if normal diagnostics fail to determine the cause of the driveability concern.
Step 1
Inspect the [1][2]PCV vacuum connector tee at the upper intake plenum hole. If loose, remove connector and install new connector, P/N 12537524. A nylon insert has been added to the connector to maintain the outside diameter. On the PCV fresh air side, a new elbow for the rocker cover to pipe connector has been released, P/N 12537523.
Step 2
Inspect the throttle cable system for proper adjustment. Cables that have excessive slack can cause a delayed throttle response which can be perceived as a hesitation. Section 6C of the Service Manual covers the adjustment of the accelerator cable.
Step 3
After inspecting the [1][2]PCV connector and throttle cable for proper operation, install a new PROM, P/N 16226503.
The following guidelines should be followed for comments of fogging on the inside of the windshield.
Step 1
Inspect the operation of the A/C compressor clutch. Step 2
If operating as intended, replace the PROM with P/N 16226503. The values for the A/C compressor clutch control have been changed from disabling the clutch based on the A/C pressure transducer pressure of 38 psi (new value 33 psi) or less. It will remain disabled until the A/C pressure transducer senses a rise in pressure to 47 psi (new value 37 psi) or greater.
Parts are expected to be available on September 4, 1995 from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation Labor Time
J6980 Vacuum Hose, Repair or Replace Use published labor operation time.
J6364 Replace PROM Use published labor operation time.