My 3.0 Megasquirt install guide!

MEGASQURT INSTALL GUIDE

As of this writing the only way to tune the fueling curve and spark curve on the 3.0 is with a standalone or a piggyback control such as a Greddy eManage. Some work is being done with the 3.0 SMEC controllers but there has been minimal progress that I’ve seen and tuning for boost seems unlikely.

First step to setting up MegaSquirt on your car is buying it. There three different boards available and there are three different processors available (at the time of this writing). All three of these processors can be used with any of the three boards but I recommend sticking with the MS2 or MS3 processor and the 3.0 or 3.57 boards. I do NOT recommend the MS1 processor or the 2.2 board; these are obsolete and not worth buying in my opinion.

If you are running an A604 automatic you will need to either run an aftermarket controller for it, such as the MS GPIO board that is currently being developed. I had some success running my ’89 604 with an ’89 TCM with my MS install. The ’89 TCM needs an rpm signal from the “low data rate” output on the stock distributor and needs a signal from the TPS sensor to work properly. For the rest of this guide I will assume that you do NOT have an A604 and are instead running an A670 3speed auto or an A543 5 speed manual.

I recommend installing a Wideband O2 sensor and Wideband Controller such as an Innovate LC-1 Digital Wideband Controller or a SLC OEM: Sigma Lambda Controller OEM if you're the adventurous type.



WHAT TO BUY


The cheapest basic setup (MS2/3.0 board) will run you about $266 + wire harness + shipping from DiyAutotune.com

http://www.diyautotune.com/catalog/i...s230-k_med.jpg


The top of the line setup with all the bells and whistles will run you about $650 + wire harnesses + shipping for a fully assembled MS3/MS3x controller.

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The basic things you need to order are:

1. The Megasquirt controller its self. Price starts at $266 and goes up from there.

2. The Megasquirt wire harness. You could make your own harness, but I don’t recommend it. DIY used automotive grade wire with excellent labels which makes installation much easier. A completed harness from Diy is $69 + shipping. I also recommend getting additional wire from Diy to populate pins 3-6 and 10-16 in their harness. These pins may be needed for adding addition inputs and outputs to MS. Alternatively, you could buy the RSAutosport harness for roughly the same price with all the pins populated, but, the RSAutosport harness availability is becoming questionable and I have had some problems with bad crimps on some of the wires.

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3. You may need to purchase some addition kits or components. You will need additional ignition drivers (BIP373) if you plan to drive more than one standard coil (3 coils for wasted spark). http://www.diyautotune.com/catalog/i...bip373_med.jpg

If you wish to use coil near plug, GM LSx coils would be the easiest to use in my opinion. The GM LSx coils are logic level coils and do not require any additional coil drivers inside the MS case.

The stock 3.0 and 52mm 3.3 throttle bodies, as well as many other OEM throttle bodies, use a stepper idle control valve. The MS2 and MS3 processors have a stepper motor driver built in but some other throttle bodies (ie. Ford) use a PWM idle valve which would require purchasing a PWM idle valve control kit (not required with 3.57 board)

4. You will need a few resistors for creating different driver circuits and for setting up your tach input from the distributor optical sensor or crank sensor if you have one. These resistors are available from DiyAutotune in the pull-up kit for $2.00.
http://www.diyautotune.com/catalog/i...pullup_med.jpg

5. You need to decide what kind of ignition setup and trigger input you are going to use with Megasquirt. You can simply use the stock distributor and single coil ignition which allows for batch injector firing and distributor ignition or you can modify your crank pulley into a toothed wheel allowing for wasted spark ignition (MS2 or MS3) and sequential injection (MS3 with the addition of a cam sensor).

I recommend going through the process of adding teeth to your crank pulley because it is fairly simple with a protractor and a drill press and provides better crank position information to MS allowing for more accurate ignition timing as well as future proofing your setup if you wish to use a more advanced setup in the future. I simply bracket with angle metal can be used to mount a sensor to the front engine bracket that can read the teeth on the crank pulley.

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You can control everything on your 12V 3.0 and completely remove you SMEC/SBEC with a basic V3.0 board and a MS2 processor. You will need to add an external voltage regulator to control your alternator (buy one for an ’84 2.2 Omni with pigtail) and you will need an aftermarket cruise control box to retain cruise control.


WHAT DO WITH ALL THE WIRES UNDER YOUR HOOD


First thing to do when installing Megasquirt is to do some pruning under the hood of your car. I recommend removing all of your fusible links and installing a Power Distribution box from a ’90-92? LeBaron. This cleans up the engine bay and puts all of your relays and under hood fuses in one convenient place.

1. Remove all the wiring associated with the A604 TCM if you had one.

2. Remove all the engine control wiring. You need to keep all the starting and charging circuits intact unless you plan on upgrading that wiring at the same time.

3. When removing all of the existing computer wiring, remember to keep all the connectors for the sensors, injectors, coil(s), ect with a short (12") pigtail on them - we will need these for the Megasquirt harness. Alternatively, you could purchase brand new Weather-Pak connectors from Ebay or Diy to make a brand new engine harness. If you are changing the type of injectors you’re going to run, remember to obtain the correct connectors with pig tails.

4. Make sure you leave all the wiring for your cars indicator lights and non computer related equipment intact. ie horn wiring, speedometer wiring, headlights, ect. Make sure to leave the cooling fan wiring intact or replace the wiring with new wires and connectors - we will need this. Also leave as much of the wiring that used to go through the firewall from the dash to the computer intact. We will need some of these wires for your tachometer, maybe speedometer, and ignition switch power.

5. After removing all this wiring you should only have a hand full of wires left under the hood of your car. At this point I recommend installing a Power Distribution box from a LeBaron / Daytona. These are available in the high optioned cars and cleans up all the under hood relays and wiring very well. These distribution boxes mount behind the battery with a nifty bracket. If you had the time you could even pull the complete harness out of a donor car with the bulkhead connectors and re-pin the harness to fit your stock bulkhead connector for a factory look. Try to get as much un-cut wiring as you can if you go this route.

If the above sounds like too much work is too daunting, MS can be installed using all the factory under hood wiring by simply removing the stock SMEC/SBEC/SBECII by cutting the 60 way connector off the under hood harness and splicing in the MS harness wires with the addition a single relay dedicated to providing power to MS right off the battery through a small inline fuse. This method works but may leave you chasing electrical gremlins for months due to unreliable 20 years old wiring and/or poor ground.


MOUNTING MEGASQUIRT AND RUNNING HARNESS

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I chose to mount my Megasquirt under my dash behind the glove box. There is a nice cavity on my Spirit that is just the right size for it. I screwed mine to the heater box with some self tapping screws.
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Alternatively, you may have room to mount MS in the passenger side kick panel. After determining where to mount Megasquirt you will need to run your harness to the engine compartment. I chose to re-use the hole where my auto shift cable went through the firewall. Whatever method you choose to use to get the wiring to the engine bay, ensure that you use a grommet to protect the wires and make sure there is a tight seal to keep noise, fumes and water out of your car.

Once the wires are under the hood you need to plan out your wire routing scheme. I ran all the power wires across to the driver’s side in what remains of the harness that runs along the top of the firewall. I ran the rest of the wires across to the engine and under the plenum. From under the plenum I ran each wire to its destination making sure to have a Megasquirt ground wire for each sensor including the crank position sensor. This makes a nice, neat, factory looking setup with no spaghetti.

It is very important that you run a sensor ground wire to each sensor location. If you look at the above picture you will see that 7-9 are ground wires and 17-19 are ground wires. Pins 7-9 should all be grounded to the same location on the engine block. Pins 17-19 are to be used for sensor grounds. For example, run pin 17 to the distributor pickup, run pin 18 wire to the coolant temperature sensors and run pin 19 to the TPS and IAT sensor. If your plenum is reversed you can tie the distributor sensor and the coolant sensor together instead. The point is to make sure that the ground for each sensor is connected to either pin 17, 18, or 19. This keeps noise out of the sensor signals.

You can get rid of your factory map sensor and bracket as we won’t be using it anymore.

Inputs

Coolant temperature sensor:

You can re-use your stock sensor or buy a new Chrysler sensor or GM sensor. Just make sure to choose the correct sensor when setting up your tune in Tuner Studio.

Connect the Black/Lt Blue wire to the Megasquirt sensor ground
Connect tan to the Yellow wire on the Megasquirt harness

Intake Air Temperature Sensor

I recommend getting an open element IAT sensor from a late model GM product. These have nice open air element sensors that are design to my push fit in a grommet (or small hole poked through intake plumbing in my setup). You could buy a 3/8" NPT GM Open Element IAT Sensor with Pigtail from Diy. If you wish to thread the sensor into the end of the stock plenum like Chrysler did on the early 3.0s, or you could installing it in your air box or intercooler piping.

Connect one wire to sensor ground
Connect the other wire to the orange wire on the megasquirt harness.

Throttle Position sensor

Connect the Violet wire to the Grey wire on the megasquirt harness.
Connect Orange/Dark Blue wire to the smaller AWG Blue wire on the megasquirt harness.

Connect the Black/Light Blue wire to the megasquirt sensor ground.

Distributor Pickup

Connect the Grey wire to pin 24 / shielded white wire on the megasquirt harness.
Connect Black/Light Blue to megasquirt sensor ground wire.
Connect the Orange wire to the same power source as megasquirt to power the distributor.
Connect the Tan/Yellow wire nowhere. This wire is not used. It could be used as a second trigger to indicate TDC to run wasted spark if you modified the inside of the dizzy, but a missing tooth wheel on the crankshaft is a more elegant solution.


Crank Position sensor pickup

If you are not using the distributor you will need to find a wiring diagram for whatever sensor you use. I found some nice VR or Hall sensors on some early 2000 Madza products that could easily be mounted to a piece of angle metal and bolted to the front engine bracket. The output from the sensor will be connected to pin 24 on the MS harness and the ground for the sensor will be connected to the sensor ground on the MS harness (the metal shield around the wire connected to pin 24 can be used as the sensor ground on the Diy harness). If you are using a hall-effect sensor (typically three wires) you will also need to connect the power wire for the sensor to the same switch power source as MS.

A cam sensor would be wired in the same way but the signal from the sensor need to be fed into MS using one of the spare pins and connected inside MS accordingly.


Oxygen Sensor

Stock Narrow band:

The O2 sensor has 4 wires to it:
Black/light blue connects to the megasquirt sensor ground
Black/dark green connects to the Pink wire in the megasquirt harness
Black wire is grounded to the engine block (use the same place as the megasquirt power ground)
White wire connects to the ASD relay wiring like the fuel injectors

Wide Band

Consult the manufacturer of your wideband controller about how to interface it with your Megasquirt. A typical winde band controller has 4 wires. +12v power, power ground, signal ground and signal. Connect the four wires just like a narrow band O2 sensor. You will need to calibrate the wide band band controller and configure the output correctly for MS and configure MS correctly for the wide band.
Configuring the wide band in Tuner Studio can be confusing as there are three different menus that you need to configure.


Outputs

Fuel Injectors

If you have the older low impedance injectors I recommend changing them at this time. The stock high impedance injectors found on the sequential injection 3.0s won’t flow anymore fuel but they are much easier for MS to drive and they create less noise. Using the high impedance injectors also allows you to eliminate many parts from the MS controller (if using a v3 board) to save cost and make more room for more useful things. If you must run low impedance injectors you can install ballast resistors in-line with the injectors or install two Peak & Hold boards inside the MS case to handle current limiting to the injectors.

Each injector will have two wires.

One wire is connected through the ASD relay (we will be reusing it either stand-alone mounted to the fender or inside the power distribution box) to +12V, the other wire is connected to Megasquirt. Megasquirt has two injector channels (MS2) or eight +two injector channels (MS3). You can choose to wire one injector bank to one channel and the other injector bank to the other channel (MS2). This is the recommended way for MS2.
If you have a MS3 processor, it is recommended that you connect all six injectors to the MS3x wire harness to allow for sequential injection (If you bought the MS3x board and harness). Low impedance injectors or high impedance injectors must be used with sequential injection. Low impedance injectors can be used with two peak & Hold boards for sequential injection but I recommend speaking with me to discuss the more involved wiring inside the MS case to make this work. MS3x board is not required for sequential injection but makes things s lot easier.

The two fuel injector channels in the Megasquirt wire harness are:

Channel 1 - the larger AWG blue wire.
Channel 2 - the larger AWG green wire.


Ignition coil:

The ignition coil has two wires.
Connect the positive ignition coil wire/terminal to the ASD relay the same as the injectors and O2 sensor
Connect the negative wire/terminal to the Dark brown wire in the megasquirt harness.
If running wasted spark or COP then each coil + wire will get its power through the ASD relay and then and the ground wide is switched through MS with an appropriate coil driver or external ignition module.

If you are using logic level coils, such as LSx coils, each coil has four wires.
A = Coil Primary Ground
B = Ignition low noise ground from ECU (ground)
C = Ignition digital signal from ECU (+5V)
D = +12V Supply to Coil Primary



Cooling fan

I recommend using the fast idle output on megasquirt to control the cooling fan relay. To do this:
Connect the cooling fan relay Dark Blue/pink wire to the small AWG green wire in the Megasquirt harness. Leave the rest of the cooling fan wiring connected as it was stock.

Stepper Idle Control

The IAC has 4 wires that need to be connected. Megasquirt also has 4 wires for the idle motor. They are: Blue / white, blue / white, green / white and green / white. Have a look at the wiring diagram provided by Diy to determine what connector you have and how to connect the IAC.
http://www.diyautotune.com/images/tech/ewIAC.gif

Tachometer

Any aftermarket tach that is designed to trigger directly from the coil will work.
The stock coil can be used if the tachout circuit is added to the MS board and enabled in the correct menu in Tuner Studio. I have been unable to get the stock tach to read correctly, however.

Setting up the distributor trigger

In Tuner Studio you should setup the idle LED to indicate IRQ. This will make it so that he middle LED will light up whenever the MS tach input is on.
You need to set the dizzy up so that the middle led turns on at whatever trigger angle you choose. If you setup the tach input on MS the way that DiyAutotune says to do it, then the trigger will stay on (middle LED stay on) for 55 degrees for rising edge or 65 degrees for falling edge trigger.
I believe falling edge trigger is the best to use. But you might need to do some trial and error.

So you need to:

Rising edge trigger:

1) Set the crank shaft to 10 degrees BTDC on cylinder #1
2) Turn the dizzy backwards until the middle LED turns on (backwards from the #1 spark terminal in the dizzy cap)
3) Turn the dizzy very slowly forward until the led just turns off and then lock down the dizzy with the bolt.
3) Set the trigger angle in MS to 65

Falling edge:

1) Set the crank shaft to 10 degrees BTDC on cylinder #1
2) Turn the dizzy backwards until the middle LED turns off (backwards from the #1 spark terminal in the dizzy cap)
3) Turn the dizzy very slowly forward until the led just turns off and then lock down the dizzy with the bolt.
3) Set the trigger angle in MS to 75


4) Set the "Cranking timing" to trigger return
5) Set the cranking advance angle to 10 in MS
6) Set a "fixed angle" of 10
7)Verify that at 10 degrees BTDC the rotor is just about to leave the #1 terminal in the cap and at 60 BTDC degrees the rotor is just arriving at the #1 terminal in the cap
8) Get the car to start
9) Verify that you have a 10 BTDC with a timing light with the engine running. Adjust the dizzy to achieve 10 degrees if needed
9) Set the fixed angle back to -10

Frequently asked Questions

Q.
“…I am in process of putting a 3L v6 w/MS2 into an '87 Shadow. The question I have right now is "Do I keep the power module?"

It seems to be able to control the alternator, so it would get rid of the need for a voltage regulator. Not sure what the other impacts would be...”
A.
Get rid of the power module and buy a voltage regulator for an early 80s carb Chrysler. IE. 84 Omni. Cost about $15 and another $5 for a new connector to go with it.

Without the logic module a power module does nothing.

Everything else except the tachometer and cruise will work without the logic module/power module. Megasquirt can drive the factory tachometer but I have problems with it reading about 30% low. For cruise I added a standalone cruise module I found on ebay
Q.
“How tough would it be to wire in the 604 controller? Can the shift points be raised?”
A.
An ’89 TCM can be used as a standalone transmission controller. It only requires an RPM signal from the stock distributor and a TPS signal to work. Reliability is questionable when used with a non-stock engine. After market 604 controllers can be found and the MS GPIO board is being developed as a transmission controller for the 604 currently.


My Install Pictures

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hey, typo tripping me out on falling edge. It needs to be 'turn the dizzay back until LED off" then "turn forward until on" It says off both times which must be what is screwing with my mind until I read both rising edge and falling edge back and forth thinking about how the on/off of the optical works and realized why following directions made no sense.

Please somebodydelete this post after fixed :P

Out back thinking my car is dumb and my MS is broke :P

Firmware ms2/extra 3.31 also required me setting trigger offset angle to 75 BEFORE doing any of this (had to be more then 60) or it gave me a configuration error. I had to set it to spark mode trigger return to enable the middle LED and this is what leads to the configuration error. Blah!