DeLorean DMC-12 Actron Dwell Meter Fuel-Air Mixture Adjustment Procedure with Chris Miles

Introduction

This tutorial will guide you through the process of optimizing the fuel-air mixture in a 1983 DeLorean DMC-12 using an Actron Dwell Meter. Proper adjustment of the fuel-air mixture is essential for achieving optimal gas mileage and ensuring that your engine runs efficiently without excessive fuel consumption or unburned fuel in the exhaust.

Step 1: Gather Your Tools

Before starting, ensure you have the following tools:

• Actron Dwell Meter
• 3mm hex key tool
• Engine diagnostic plug (with orange and purple wires)
• A way to safely ground the negative lead (the AC bracket works well)

Step 2: Connect the Dwell Meter

1. Connect the negative lead of the dwell meter to the engine ground. A good spot is the bracket for the AC.
2. Connect the positive lead to the orange wire of the diagnostic plug. This wire connects to terminal No. 17 on the Lambda ECU, which is vital for monitoring the fuel system.

Step 3: Start the Engine

1. Start the engine and allow it to reach operating temperature. This transition to closed loop operation is necessary for accurate readings.
2. Observe the dwell meter. It should start swinging, ideally between the 15 to 20 mark on the scale. Note that for measurement purposes, these values should be doubled (15 on the scale corresponds to a reading of 30).

Step 4: Make Adjustments

1. If the needle swings below the desired range (15-20), you need to make adjustments.
2. Use the 3mm hex key tool to turn the adjustment screw:
   • Turn counterclockwise to enrich the mixture (add more fuel).
   • Turn clockwise to lean out the mixture (reduce fuel).
3. Continue to monitor the dwell meter as you make adjustments, aiming for the needle to stabilize within the 15-20 range.

Step 5: Final Checks

1. Once you achieve a stable reading within the desired range, ensure that the engine does not emit excessive unburned fuel from the exhaust.
2. A well-adjusted fuel-air mixture should lead to improved gas mileage and optimal performance.

Conclusion

By following these steps, you’ll ensure that your DeLorean’s fuel-air mixture is optimized, leading to better performance and fuel efficiency. If you encounter any issues or have questions during the process, consider reaching out for further assistance or checking out more resources on DeLorean maintenance. Happy driving!