Delaying the Switch to LPG

Delaying the Switch to LPG in Cold Climates

Optimizing the Engine Management System: An Experimental Approach with Arduino

Introduction

This work describes an experimental implementation aimed at optimizing the behavior of a dual-fuel vehicle (gasoline/LPG), such as my 2020 Ford Fiesta bi-fuel. Specifically, it addresses the issue of premature switching to LPG under low ambient temperature conditions, a common phenomenon that can negatively affect engine performance, especially during the first few kilometers in cold weather.

Materials and Methods

Hardware Platform: Arduino Nano, mounted on a MAK-NANO2RL-107 breakout board purchased as a kit on eBay. This choice was made due to its compactness and the flexibility offered by the breakout, allowing for rapid prototyping.
Temperature Sensor: The engine management system's integrated NTC temperature sensor was utilized. When not connected to the ECU, it was still readable by Arduino.
Resistor: A 47 kΩ resistor was used to simulate a lower temperature, tricking the ECU into maintaining gasoline fueling.
Watchdog: A WATCHDOG32 module, also purchased on eBay, was integrated to ensure system stability and prevent potential crashes.

Methodology

Problem Analysis: An analysis of the engine management system's behavior under different operating conditions was conducted, focusing on the warm-up phase and the switch to LPG. Voltages and resistance values of the NTC were recorded.
Circuit Design: An electronic circuit based on Arduino was designed to read engine temperature, compare it to a predefined threshold (adjustable via a trimmer), and command the switch to LPG only upon reaching the threshold.
Software Development: A program for Arduino was developed to implement the temperature control algorithm and manage the interface with hardware components.
Prototype Development: The circuit was built on a MAK-NANO2RL-107 breakout kit, ensuring proper component connections and electrical isolation.
Testing and Calibration: The prototype underwent extensive testing under various operating conditions to verify functionality and calibrate the system parameters.
Onboard Installation: Once validated, the prototype was installed in the vehicle, integrating it into the original circuitry.

Results

The results showed a complete resolution of cold-start issues, eliminating premature switching to LPG and resulting in improved efficiency.

Conclusions

This experiment demonstrated how Arduino can be used to create customized and innovative solutions for optimizing vehicle performance. The experimental approach allowed for the development of a flexible system adaptable to various needs.

I understand that tampering with vehicle devices is prohibited, as all components must be homologated. However, this project was undertaken purely for experimental and educational purposes, to explore the challenges of turning an idea into a working implementation. The circuit was initially tested with a wired prototype, then finalized using the MAK-NANO2RL-107 breakout, and subsequently removed from my car. I plan to reuse it for other purposes.

All project details and the sketch can be found at: https://www.hackster.io/pautax/delay-switching-to-lpg-with-arduino-nano-9524cf