MJLJ V3 Operation Guide

Revision as of 18:51, 25 November 2007 by Brentp (talk | contribs) (added runtime section)
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First time use

Installing Configuration Software

Download the version of the Configuration software that matches your controller firmware. It's likely you have a very recent firmware image, so start by downloading the latest version of the Configuration software.

Setting the Serial Port

Find and run the Configuration software by finding the icon under the Start Menu program group. Once the program is running, you can set the serial port the MJLJ is connected to by clicking Tools/Configurator Options.

Mjlj controller options screenshot.png

If you don't know which COM port you have the MJLJ connected to, you can discover this under Windows Device Manager: Find the 'My Computer' icon, right-click and select Properties. From this window you will be able to access Device Manager.

Expand the 'Ports (COM & LPT)' to see the list of installed COM ports.

Windows device manager screenshot showing com ports.png

Once you're certain which COM port you're using for the MJLJ, select this value in the options dialog.

Configuring MAP or TPS

In the Controller Options dialog, select the Load type you have for your MJLJ- Throttle Position sensor(TPS) or Manifold Absolute Pressure (MAP).

Configuring Normally Aspirated or Forced Induction

Check the 'Normally Aspirated' box if that matches your engine type. This setting will scale the load axis for the runtime and logging views to 103KPa maximum.

Otherwise, select 'Forced Induction' if your engine is turbocharged or supercharged. This will set the maximum scale to 255KPa (about 21 PSI of boost)

Connecting to the MJLJ

Verifying Connectivity

After the COM port has beens et, connect the serial cable to the MJLJ and apply power. If you already have the MJLJ wired into your engine's wiring harness, turn the ignition key to 'on'. If you are testing the MJLJ on the bench, you can simply power the unit with a 9V battery or a suitable 9-15V power supply.

The first way to verify connectivity is to observe runtime data on the screen. On a running engine you'll see the real-time RPM, load and ignition advance values on the gauges at the bottom of the window.

If you're testing on the bench or on a non-running engine, you will still be able to observe some runtime activity by simulating load changing on the engine. For TPS- move the accelerator pedal; MAP- you can manually apply pressure or vacuum.

Mjlj main screen connected.png
Successfully connected to the Megajolt Lite Jr.


Common connection problems

If the Configuration Software cannot connect to the MJLJ, you will see one of the following messages in the status bar:

Timeout reading runtime data

The Configuration Software did not get a response from the MJLJ on the serial port you specified.

Could not open port

The Configuration Software could not access the serial port you specified.

Either:

  • The port is invalid: Check Device Manager for the proper serial port.
  • Serial port in use: If another program is using the same serial port your computer will block the Configuration software from accessing the serial port. Check that you don't have any other software which may open and use the serial port you're trying to use, such as PDA sync software.

Monitoring Engine Runtime

Operation guide config software runtime screen reference.png
Runtime view

Working with the Ignition Configuration

Retrieving the Ignition Configuration

To read the controller's current configuration, click the toolbar icon Mjlj read config toolbar.jpg. The current ignition configuration will be read from the MJLJ and displayed in the grid.

Ignition Map

The ignition map organized as a 10 x 10 grid of ignition advance values, with Load/RPM bins defining the steps between grid values.

  • Load Axis: The Load axis is is represented vertically, from low engine load at the top to high engine load at the bottom.
  • RPM Axis: The RPM axis is represented horizontally, from low RPM on the left to high RPM on the right.
  • Bins: The steps between engine load and RPM points are defined as 'Bins'- these are the values shown along the borders of the Ignition Map grid.
  • Ignition Advance: Each cell in the grid represents an ignition advance value, in actual degrees before top dead center (BTDC).

Options

Updating the Ignition Configuration

Making the changes permanent

Configuration Options

Configuring TPS

Choosing between Normally Aspirated and Forced Induction

Switchable Ignition maps

Tuning your Ignition Controller

Ignition Map View

Runtime View

Tuning View

Data logging

Advanced Topics

Configuring PIP noise filtering