Engine - Rough Idle

91chevy08

Number: 90-408-6E


Section: 6E


Date: March 1991


Corporate Bulletin No.: 136503


Subject: IDLE ROUGHNESS


Model and Year: 1990 CAPRICE WITH 5.7L TBI


Condition: Some owners of 1990 B cars with 5.7L (VIN 7, LO5 V8) engine may comment about idle roughness. This condition may be more prevalent at altitude.


Correction: The calibration has been refined to address idle speed control. Replace the PROM with the following part number.

Broadcast Scanner Part
Code I.D. Number Body Application
AXWD 2831 16162838 5.7L LO5 Nationwide Emissions

Parts are currently available from GMSPO.

Labor Operation: T0500

Labor Time: 0.5 Hours

Trouble Code: 92