If you are new to Megasquirt, it can be a bit intimidating trying to navigate through the wiring process. This guide is here to help you understand how to wire your Megasquirt ECU to your engine like a pro.
What is Megasquirt?
Megasquirt is a standalone Engine Control Unit (ECU) that allows you to control fuel and ignition timing. It is an open-source system that is customizable to fit any engine configuration.
It is a popular choice among tuners and enthusiasts as it offers a high level of control over your engine settings without the need for expensive proprietary software and hardware.
The Megasquirt Wiring Diagram
The Megasquirt wiring diagram is divided into several sections that correspond to specific engine components. These sections include:
| Section | Description |
|---|---|
| Power | Wiring for power supply and ground. |
| Sensors | Wiring for engine sensors such as the Crankshaft Position Sensor (CPS), Camshaft Position Sensor (CMP), and coolant temperature sensor. |
| Injectors and Coils | Wiring for fuel injectors and ignition coils. |
| Fuel Pump | Wiring for the fuel pump relay and fuel pump. |
| Inputs and Outputs | Wiring for additional inputs and outputs such as the tachometer, throttle position sensor (TPS), and boost control solenoid. |
Wiring the Power Supply
The first section of the Megasquirt wiring diagram is the power supply. This section includes the input voltage, ground, and power supply relay. Here is how to wire the power supply:
1. Connect the power supply wire (usually red) from the Megasquirt ECU to a switched 12V source.
2. Connect the ground wire (usually black) from the Megasquirt ECU to a clean ground source.
3. Connect the power supply relay to a fused 12V source.
4. Connect the power supply relay to the Megasquirt ECU power supply wire.
Wiring Engine Sensors
The second section of the Megasquirt wiring diagram is the engine sensors. This section includes the Crankshaft Position Sensor (CPS), Camshaft Position Sensor (CMP), and coolant temperature sensor. Here is how to wire the engine sensors:
1. Connect the CPS signal wire to the Megasquirt ECU input for the CPS.
2. Connect the CMP signal wire to the Megasquirt ECU input for the CMP.
3. Connect the coolant temperature sensor signal wire to the Megasquirt ECU input for the coolant temperature sensor.
4. Connect the sensor ground wires to a clean ground source.
FAQ
What size wire should I use for the power supply?
You should use a minimum of 14 gauge wire for the power supply. This will ensure that you have enough current to power the Megasquirt ECU.
What size wire should I use for the sensors?
You should use a minimum of 20 gauge wire for the sensors. This will ensure that the signal is not degraded over the length of the wire.
Do I need to connect all the sensors to the Megasquirt ECU?
No, you only need to connect the sensors that are necessary for your engine configuration. However, it is recommended that you connect as many sensors as possible to get the most accurate readings.
Wiring your Megasquirt ECU can be a daunting task, but with this guide, you should be able to confidently wire your engine like a pro. Remember to take your time and double-check your connections before starting your engine.
