Engine - Temporary DIP/SAG with Warm Engine
File In Section: 6E - Engine Fuel & EmissionBulletin No.: 57-65-26
Date: January, 1996
Subject:
Temporary DIP SAG with Warm Engine (New "FLASH" Calibrations)
Models:
1996 Chevrolet and GMC Truck S/T Models
with 4.3L V6 Engine (VINs W, X - RPOs L35, LF6)
Condition
Some owners may comment on a driveability condition known as TEMPORARY dip or sag on a warm re-started engine, after approximately a one hour soak.
The condition dip or sag is described as a lack of engine response at a particular throttle position. The engine may stumble and perform poorly.
This condition may be noticeable at a steady, light throttle operation and be noticeable for 30 seconds to a minute, after which time the condition completely disappears.
Cause
The engine is running in a closed-loop status when the oxygen sensors are not fully operational.
Correction
New "FLASH" calibrations were released in production vehicles during September, 1995. Vehicles exhibiting this specific driveability concern should be updated with the new calibrations as shown.
Standard diagnostic procedures and trouble shooting flow charts should be used when servicing these vehicles with the new calibrations.
Service Information
The service "FLASH" calibrations are available starting with the October, 1995 CD ROM. These calibrations are NOT available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation Labor Time
J-6355 0.3 hr