Engine - Decel Stall/Long Crank on Start Up
Bulletin Number: 93-6-5Reference Number: 206504
Publish Date: 10/91
Subject:
DECEL STALL/CRANK ON STARTUP NEW IAC MOTOR
Models Affected:
ALL 1988-1993 3800 AND 1992-93 3300 ENGINES
1988-93 BONNEVILLE, GRAND AM AND TRANS SPORT MODELS
1988-91 BONNEVILLE VEHICLES EQUIPPED WITH 3800 (VIN C) ENGINE 1992-93 GRAND AM VEHICLES EQUIPPED WITH 3300 (VIN N) ENGINE 1990-93 BONNEVILLE VEHICLES EQUIPPED WITH 3800 (VIN L) ENGINE 1992-93 TRANS SPORT VEHICLES EQUIPPED WITH 3800 (VIN L) ENGINE 1992-93 BONNEVILLE VEHICLES EQUIPPED WITH 3800 S/C (VIN 1) ENGINE
Some of the models mentioned above may experience a decel stall or long crank on startup. This condition can sometimes be viewed on a scan tool as excessively high IAC counts at idle immediately after startup, or as a failure to return to the same (or similar) IAC counts displayed at idle after several throttle maneuvers.
If this condition is experienced and currently published service diagnostic procedures indicate a malfunctioning IAC motor, it will be necessary to install a new IAC motor.
It should be noted that two designs of IAC motors exist. The 3800 (VIN L) and the 3800 supercharger (VIN 1) use a triple slope design (see figure). The 3800 (VIN C) and 3300 (VIN N) use a dual slope design. The dual slope and the triple slope designs are not interchangeable. Several part numbers for IAC motors are being phased out to standardize usage and are being replaced by current production IAC motors. The chart below lists the application and appropriate service part numbers.
Parts are currently available from GMSPO.
WARRANTY INFORMATION:
Use applicable Labor Operation and Time.