Plug-N-Play Standalone Engine Management System

MSPNP models MM9093, MM9495, and MM9697 covering the 1990-1997 Miata

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MegaSquirtPNP MM9093 Quick Start Guide

While the manual (included on the CD-ROM) gives the full details of how to set up and tune your MSPNP, this Quick Start Guide gives you the basics of whatís involved. The CD-ROM will install the tuning software and the full version of the manual.  Itís a good idea to get the software installed before installing the MSPNP, as itís very helpful when getting the timing set.  Your MSPNP connects to the computer with the supplied tuning cable.

  1. To install the MSPNP on the car, you will need to remove the ST SIGN fuse from the underhood fuse box. Do not, under any circumstances, run the MSPNP with this fuse installed. Doing this will cause damage to the MSPNP. YOU MUST REMOVE THIS FUSE.

Remove the ST SIGN fuse


  1. Next, you will remove the stock ECU, located under the passenger side carpeting on the firewall. The MSPNP plugs into the stock wiring harness, and you will also need to run a line for the MAP sensor (located on the side of the MSPNP unit). The MAP line runs from the nipple on the throttle body used for cruise control (use the included tee if you have cruise control), thru an existing hole in the firewall, to the MAP sensor accessible through the hole in the side of the MSPNP ECU. The pictures below show a suggested routing for the MAP line.

    MSPNP Suggested MAP line routing MSPNP MAP Port


  2. Turn your key to the ON position, but don't start the car yet.  Plug the tuning cable into the MSPNP, and into your laptop or PC.  Install the software on the supplied CD-ROM and then run MegaTune.  Select the correct 'project' for with or without AFM (most likely with at this point) and once MegaTune loads open the Communications Menu and choose Settings.  Select the correct COM port you've plugged the MSPNP into (check Device Manager for a list if you need it) and verify the 'Serial Data Rate' is set to 9600.  Click the 'Click to Test' button and you should get a 'Success' Message.  If not you've probably selected the wrong COM port.  Find the right one before you continue.
  3. Start the car (it should start with no tuning changes on engines with the stock injectors) and set the base timing. Setting the timing will be easiest to do with MegaTune connected to the MSPNP, as you can adjust the timing within MegaTune. Connect to the MSPNP with the tuning software, go to the Spark Settings menu and set Fixed Angle to 10, then adjust the Trigger Angle until you read 10 degrees with a timing light. If the trigger angle needs to be less than 50 degrees to get your base timing right then set trigger angle to 55 and instead adjust the cam angle sensor to set your base timing, just like adjusting timing on a stock Miata. Then set Fixed Angle back to -10 to enable spark advance. Itís very important to get the base timing set correctly, as running with the incorrect timing advance can damage your engine.  See the manual for full details on setting base timing, including a video.


  1. Once you have the engine running and the timing set, youíre now ready to start tuning. The base map was developed for a stock Miata, but youíre best off tuning the engine (ideally by a qualified tuner on a steady-state chassis dyno) before you really push it hard. For more details of whatís involved in tuning the MSPNP and how to use the features it offers such as the ability to eliminate the AFM, see the full manual on the CD. In factÖ for more information and the installation process in detail, see the manual on the CD-ROMÖ


MSPNP MM9093 Full Manual Available Online Here



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The MegaSquirtPNP, as with any programmable engine management system, may not

be legal for use on pollution controlled vehicles and is therefore produced and sold for off road/race use only.  Check federal/local laws.


MegaSquirtPNP, MSPNP, MegaSquirt PNP, and MS PNP, are trademarks of Hoffmann Innovations, Inc d/b/a