Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSCHEVROLET1993ASTRO VAN L AWD V6-262 4.3L VIN W CPIREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSADJUSTMENTS
1993 Chevrolet Astro Van L AWD V6-262 4.3L VIN W CPI
Computers and Control Systems: Adjustments
1993 Chevrolet Astro Van L AWD V6-262 4.3L VIN W CPISECTION Adjustments
CONTROLLED IDLE SPEED CHECK
NOTE Before performing this check:
- Verify no codes displayed
- Idle air control system has been checked
- Ignition timing is correct
PROCEDURE
- Set parking brake and block drive wheels.
- Connect a SCAN tool to the data link connector (DLC), connect with tool in Open Mode.
- START engine and bring it to normal operating temperature.
- Check for correct state of PARK/NEUTRAL switch on SCAN tool.
- Check specifications chart for controlled idle speed and IAC valve pintle position (counts).
- If within specifications, the idle speed is being correctly controlled by the control module.
- If not within specifications, refer to DIAGNOSIS, TESTING AND INSPECTION PROCEDURES / TESTING PROCEDURES / DIAGNOSIS BY SYMPTOM / ROUGH, UNSTABLE OR INCORRECT IDLE.
MINIMUM IDLE AIR RATE CHECK
Minimum Idle Air Rate is not adjustable on this engine.
CONTROLLED IDLE SPEED
Body Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2]
M D 550 5-40 CL
L D 625 15-50 CL
[1] Add 2 counts for engines with less than 500 miles. Add 1 count for every 1000 ft. above sea level.
[2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop).
NOTE Before performing this check:
- Verify no codes displayed
- Idle air control system has been checked
- Ignition timing is correct
PROCEDURE
- Set parking brake and block drive wheels.
- Connect a SCAN tool to the data link connector (DLC), connect with tool in Open Mode.
- START engine and bring it to normal operating temperature.
- Check for correct state of PARK/NEUTRAL switch on SCAN tool.
- Check specifications chart for controlled idle speed and IAC valve pintle position (counts).
- If within specifications, the idle speed is being correctly controlled by the control module.
- If not within specifications, refer to DIAGNOSIS, TESTING AND INSPECTION PROCEDURES / TESTING PROCEDURES / DIAGNOSIS BY SYMPTOM / ROUGH, UNSTABLE OR INCORRECT IDLE.
MINIMUM IDLE AIR RATE CHECK
Minimum Idle Air Rate is not adjustable on this engine.
CONTROLLED IDLE SPEED
Body Gear Idle Speed IAC Counts [1] OPEN/CLOSED Loop [2]
M D 550 5-40 CL
L D 625 15-50 CL
[1] Add 2 counts for engines with less than 500 miles. Add 1 count for every 1000 ft. above sea level.
[2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED loop).
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.