G 20 Van V6-262 4.3L VIN Z (1993)
Idle Speed: Adjustments
CONTROLLED IDLE SPEED CHECK
1.
Set parking brake and block drive wheels.
2.
Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode.
3.
START engine and bring it to normal operating temperature.
4.
Check for correct state of PARK/NEUTRAL switch on SCAN tool.
5.
Check specifications chart for controlled idle speed and IAC valve pintle position (counts).
6.
If within specifications, the idle speed is being correctly controlled by the ECM.
7.
If not within specifications, refer to DIAGNOSIS BY SYMPTOM/DIAGNOSIS AND TESTING PROCEDURES/ROUGH, UNSTABLE
OR INCORRECT IDLE.
UNDER 8500 GVW
CONTROLLED IDLE SPEED
Transmission
Gear
Idle Speed
IAC Counts [1]
OPEN/CLOSED Loop [2]
Auto
D
538
5-30
CL
OVER 8500 GVW
CONTROLLED IDLE SPEED
Transmission
Gear
Idle Speed
IAC Counts [1]
OPEN/CLOSED Loop [2]
Auto
D
650
20-35
CL
[1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level.
[2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop).
MINIMUM IDLE AIR RATE CHECK
Minimum Idle Air Rate is not adjustable for this engine.
