DIYAutoTune.com Engine Management Systems & Tools

 

 

 

 

 

 

 

 

DIYAutoTune.com Frequently Asked Questions (FAQ)

Updated 10/09/2008  A couple of updates made to the Innovate section...

 

Understanding the MegaSquirt and Making the Right Choice

 

MegaSquirt Tech

 

How DIYAutoTune Configures it's Assembled MegaSquirt ECUs

 

WideBand o2 / Oxygen Sensor Systems from Innovate Motorsports

 

Shipping & Customs

 

 

 

Technical Articles that should really be a part of this FAQ, but would make it too huge!

MegaSquirt Tech Article -- Will the MegaSquirt work with my stock ignition system???

MegaSquirt Tech Article -- Troubleshooting MegaSquirt Communications Issues

MegaSquirt Tech Article -- Common MegaSquirt Modifications

 

More (less FAQ worthy) Tech Articles, including full "how to's" for certain vehicles

 

 

 

FAQ

 

Understanding the MegaSquirt Engine Management System and choosing one that is right for you:

 

What the heck is a MegaSquirt?

The MegaSquirt line of Engine Management Systems are Do It Yourself (DIY) systems capable of full standalone engine management a a fraction of the cost of the what the 'big dogs' charge.  They were designed with education and performance in mind, so that the do it yourselfer could learn the in's and out's of engine management and tuning, while learning a good bit about electronics in the process.  What you end up with is an incredibly performing EMS that you built yourself for ultimate bragging rights when you leave your buddies behind as a speck in your rearview mirror.  And you did this for a quarter to a tenth of the cost of a retail standalone ECU. 

Building and installing a MegaSquirt EMS will require that you do some homework.  Some of the questions and answers below will help to guide you on where to start this and how to go about it.  You will learn alot in the process and if you so choose you will come out of it with the knowledge to properly tune your car for the current configuration you have now, and for any future power combo you can dream up and implement.  There is no limit to what you can do or to how much power you can make with this engine management system.  I know right now of a MS user running low 10's (10.08) in a 5000lb 4x4 truck making over 1000hp and 1000lbs/torque to the wheels (turbo/nitrous) who took first place in his class at Hot Rod's Drag Week 2005 and won a high dollar ($2400+) big-name EMS system in the contest, he quickly traded it away to stick with his MegaSquirt, which he has a total of around $200 invested in.  I've got another customer making about the same level of power now on one of these units, still tuning and aiming for close to 1200whp.  Preparing for Bonneville this year for two 245MPH runs.  (Check out Gary Hart's car out at this link). This MegaSquirt thing is no joke.

 

Where do I start?

Read.  Then read some more.  If you skip this step you will be asking questions later that you could already know the answers to.  I'm always glad to help though as this is a DIY based system some of the burden does fall on the user to do their homework, the big dogs charge an extra $2000+ for their systems to do some of the homework for you.  I'll help you with your homework for free, but you've got to come up with the final answer.

Start with the MegaSquirt FAQ at www.megamanual.com

Then read, cover to cover, The MegaManual at that same link: http://www.megasquirt.info/  (Note this focuses mainly on the MS-I, you can skim the assembly section)

Then read the MS-II pages that were added to the MegaManual: http://www.megamanual.com/ms2/index.htm

Then read about MegaSquirt-N-Spark Extra (MSnS-E).  This is a free firmware update for the MS-I that allows for fuel and spark control as well as a ton of other features.  It also supports some stock ignition systems that the MS-II is not currently able to support.  It is often a bit more of a technical path to travel with mods required in some cases for different features and ignition systems, but supports some ignitions systems and certain features that the MS2 doesn't yet such at boost control, launch control, knock retard, etc.  Check out this link for more info:  http://www.msextra.com/doc/ms1extra/MS_Extra_Manual_Index.htm

Now that you've read up on things start lurking around and/or asking any remaining questions on the MegaSquirt Support Forums at www.msefi.com, there is so much helpful information here that it's insane.  The search feature is your friend though it doesn't seem to like more than single word searches right now (I'll look into that).  Try searching for your vehicle or engine, 'RX7', or 'Subaru', or '4AGE' and then go through the threads that are returned.  There are a ton of very helpful people on these forums that will bend over backwards to make sure your project is successful, IF they can tell you've 'done your homework' and you're not expecting them to do all of it for you.  Questions like, "My car has an optical crank sensor in the distributor with one hole for each cylinder, spaced evenly apart.  Will the MegaSquirt-II work with this signal?" will usually get very quick and helpful responses.  On the other hand, questions like "What do I need to make my 1993 Sooper Dooper Pooper Scooper go faster?" generally get ignored because it's obvious the person didn't put much effort into helping themselves and that they are hoping someone will just pour out a magical answer for them to help their Sooper Dooper Scoop Poop faster.

You can also Contact Us and I'll do my best to assist you.  Please see the list of questions below that will help me to help you.  The more prepared you are and the more you know about your car and your ignition system the better off we'll all be and the faster we'll be able to get you up and running!

 

What do I need?

Another question that doesn't have a quick short answer... but the quick short answer is:  An ECU (there are a few options), a stimulator (95% required), and a tuning cable.  Optionally you may need a USB-Serial Converter if your laptop doesn't have a DB9 serial port, and/or a Wideband O2 system such as the Innovate LC-1 or LM-1 (with or without a dash mount gauge) which will make tuning your Air/Fuel Ratio SO much easier and more accurate that you'll be glad you spent the couple of bills to do it.

Click Here to see a page I put together to assist people in these decisions-- It doesn't cover all of our products but it does cover some of the more commonly needed ones at a high level and provides pricing current as of today (08-17-07).  For a complete product list, to validate current pricing and/or to place an order go to http://www.diyautotune.com/catalog.

 

How difficult is it to assemble a MegaSquirt myself?

It takes most people new to electronics assembly 6-10 hours for their first time assembly of a PCBv3 ECU, a bit less for a PCB2.2, and the stimulator (which you should do first) is very simple and takes maybe an hour to assemble for a first-timer.  I'd recommend going to www.google.com and querying for 'Soldering Technique' and reading up a bit, and maybe pickup up a cheapo practice kit if you want to practice your technique a bit before starting in on the MegaSquirt.  I do highly recommend you build your own at least the first time around as it will familiarize you with the hardware particularly if mods are going to be required for your implementation.  This way it's not all new to you when you get to the mods which in some cases aren't laid out quite as step by step as the main assembly.

 

I have a (insert year, make and model here), what exactly do I need to order for my car?

I'll be glad to help you spec a system for your car but I'll first need some information from you as I unfortunately don't have hands on experience with every car out there.  Below is a list of the questions I will generally need answers to in order to assist with this.  You can find this information in service manuals for your car/engine, on message boards and enthusiast sites, or sometimes by tearing into your ride and looking.  It will be a big help if you've followed the steps in the 'Where do I start?' section above so that you have a pretty thorough understanding of the MegaSquirt line of Engine Management Systems and you may find that you've answered your own questions by the time you've done this.  At any rate these are some of the questions you will need to ask yourself, and that I would need to know the answers to in order to be able to assist you:

(Please try and answer all questions as the two most people skip (3&4) are the most important for ignition control!)

  1. What year/make/model/engine/tranny? (Pretend your at the parts store, ordering a starter.)  If this isn't the original engine/electronics let me know that too.
  2. Are you looking to control fuel only, ignition only, or fuel and ignition? Is there anything beyond these features that you are looking to control - fans or boost, for example?
  3. What are the engine details (type, number of cylinders, previously fuel injected or carb'd?)
  4. What type of ignition system does your car run- where is the crank angle sensor (CAS) or distributor trigger wheel, and what type is it (Optical/LED Sensor? Hall Sensor? VR Sensor?)
  5. How many teeth/windows/slots and what orientation does the CAS, crank trigger, and/or distributor wheel have? (any missing?  all evenly spaced?)
  6. Is there a distributor?  Single/Multiple Coils?  Coil on Plug?
  7. Does this engine have a fast idle valve (IAC)? If so, how many wires are connected to it?
  8. Rate yourself 1-5 on technical confidence in yourself.  1 being "I can't paint by numbers" and 5 being "I can probably build a car from scratch if I have the right documentation, and I'm resourceful enough to do some research and find some of my own answers."  I need to know this as some of the 'less traveled' roads will require you to make modifications that in some cases I haven't performed myself yet and based on this response it will help me to know whether this type of solution is for you or not.  I challenge you to 'stretch yourself' a little bit.  You won't ever learn anything (about yourself and your abilities) if you don't try to do things that you're not quite sure you can do... and then find that you can.
  9. Are you looking to build your own ECU from a kit or buy a pre-assembled ECU?
  10. Are you open to retrofitting a different ignition system such as the Ford EDIS distributorless system or one of our crank trigger kits if it is determined that the MegaSquirt will not properly (or easily) control your factory ignition system?  Many factory systems MegaSquirt can simply take control of, some it cannot.  EDIS to the rescue!  It's cheap, simple and works great!

If you can cut and paste the above list into an email and answer all questions it would be very helpful to me-- otherwise I'll just have to ask you the same questions more than likely in order to best be able to assist you.

Also-- Here is a page we maintain with links to installation documentation for various different vehicles that I've found around the web-- If you find or write install docs that we can add here please let us know.  This is a good place to check for information that just might help you 'squirt your ride.  Even if it's not an exact match there is much to learn by looking over other's installations and notes.

 

What is the difference between the MegaSquirt PCB 2.2 / PCB 3.0 / PCB 3.57?

They are all three able to use the MegaSquirt-I CPU or the MegaSquirt-II daughterboard, but they are based on different versions of the circuit board.  You can click on any of the headings to view an example of the product with pictures.

PCBv2.2

The v2.2 board dates back several years, it's the least expensive of the currently available options, and the least developed.  It's a great low budget solution that has served many people well (and continues to).

 

PCBv3.0

The v3.0 board has a lot of improvements made to it to reduce electrical noise and increase robustness, as well as make the board easier to expand.  All of the improvements with the V3.0 board are listed here.

The main high level differences are that the uprated flyback circuitry is included so you can run low or high impedance injectors, there are several improvements to make the board more robust and harder to damage in the event of a mis-wire or overload event. A prototyping area was adding to the PCB, and several changes were made to prepare the board for the future including the now available MegaSquirt-II CPU and upcoming releases such as the GPIO and Router boards.

 

PCBv3.57

The v3.57 board's major claim to fame is it's 'surface mount (SMT)' design.   Otherwise it is almost identical to the v3.0 board and the above information on the v3.0 board fully applies.  The only other major differences are:

A) the addition of a PWM capable idle control transistor allowing control of a PWM idle valve or a standard on/off type FIDLE valve without need for modification.  This was a common modification applied to the v3.0 board and is no longer needed on the v3.57.

B) the addition of a DB15 connector next to the DB9.  By default this doesn't do anything, but is there to allow for extra I/O for modifications.  It takes the place of the externally viewable LEDs, which are now internally surface mounted on the PCB.

C) Several signal pads have been added making common modifications easier.

D) The prototype area was sacrificed (removed) to make all of the above possible.

 

 

I want a MegaSquirt-III but the newest thing I see on your site is the MS-II.  What gives?

The MegaSquirt-III exists, but is in limited release. You can learn more about it at www.ms3efi.com

In the past, there has sometimes been confusion coming from the circuit board (PCB) versions which are now 3.0 or 3.57.  The latest processor currently available is still the MS-II.  Hence the latest, greatest hardware available is the MegaSquirt-II, with PCBv3.0 or 3.57.

Everything is versioned to help keep track of things, and it gets a little confusing at times...  The MS-I firmware is at version 3.0, the MS-II firmware is only at version 2.88.  Does that mean the MS-II firmware is older?  No way, it just hasn't been around as long, therefore not as many versions have been released. 

 

How big is the MegaSquirt case?

The box is 6.2” x 4” x 1.75” with mounting flanges on each end that are about .5” long, so total length including flanges is about 7.2”.

This applies for the MS-I and MS-II, with either PCB.

 

 

MegaSquirt Tech:

 

How does a MegaSquirt compare to having my car 'Chipped'?

It is possible to get many of the same performance benefits of the MegaSquirt by having your car chipped IF the tuner chipping your car has your car onsite and custom tunes the map for your specific configuration on a steady state/load bearing dyno.  If you are not the hands on type, or you don't plan to EVER modify your car/engine again, then this is not a bad option.  If you do ever mod your car again it will likely need to be re-chipped, on a dyno by a qualified tuner, to get the maximum performance out of it.  If you simply send your ECU off to a chipping company who is supposed to load a map on your car that was NOT designed specifically for  your car on a dyno by a qualified tuner then you are simply not going to get the maximum performance possible out of the engine.  They simply can't do it-- they have to make alot of assumptions with no scientific testing on YOUR car. 

However, if you really want to take control of things, if you do have plans to further modify your car and you don't want to have to pay someone to rechip it every time you mod it, and if you want to learn something in the process then by all means a standalone EMS is the way to go.  And there is no more powerful system per dollar spent than the MegaSquirt, in fact even with the affordable price out of the picture the MegaSquirt line of Engine Management Systems rival the featureset of many aftermarket 'high dollar' systems.

 

Don't I need sequential injection to make big power?  Does the MegaSquirt offer this?

Sequential injection attempts to only spray fuel while the intake valve is open for the cylinder that is about to fire, which in most cases is only possible at very low engine speeds between idle and low speed cruising.  It can have minor benefits in emissions and fuel economy at these low engine speeds.

Batch injection (which is what the current gen MS does) does not attempt to spray only when the valve is open as it's nearly pointless, particularly for more performance oriented applications.  The fact is that at higher engine speeds 99% of sequential systems (exceptions being race only systems with super massive injectors) cannot spray all of the fuel needed while the valve is open anyways, and sprays it both while the valve is opened and closed, very much like a batch system such as the MS. 

There is no significant performance difference with a sequential system over a batch system, there can be minor emissions and fuel economy benefits at very low speeds though....  As you'll see in the next couple of questions though you can do very well with emissions and fuel economy with the MegaSquirt as well, it's all in what you tune for. 

 

Is the MegaSquirt Engine Management System just for making more power?  Or can I get better gas mileage out of it too?  What about emissions?

MegaSquirt Engine Management Systems are most often installed in the pursuit of power gains, but often economy gains are just a possible.  In fact due to the nature of programmable fuel injection usually you can achieve some of both, power when you are on the throttle, economy when you are lightly cruising around town.  It’s really all in the tune.  The factory will have tuned your engine to run around at 14.7:1 air/fuel ratio (AFR).  This is the ‘chemically correct’ or ‘stoicheometric’ (stoich for short) AFR which basically means this is the air/fuel mixture at which the most complete burn of the fuel will occur.  It’s also the proper mixture for the catalytic converter to best be able to do it’s job, in other words, you car comes tuned from the factory for reduced emissions.  If your goal is power, you’ll be tuning a somewhat ‘richer’ mixture than this, for a naturally aspirated car this is usually in the 12-13:1 range under throttle.  For economy you’ll tune somewhat leaner than this, some say the magic number is as lean as 16.5:1, or maybe even a bit leaner when lightly cruising on the highway.  That can lead to quite an improvement in highway mileage over the factory 14.7:1 tune.  Not all engines like to cruise this lean so your ‘mileage’ may vary, my MR2 doesn’t seems to love 16:1 on the highway-- I was able to get 34.5 MPG on a recent 1100 mile trip at an average speed of 70 MPH, a decent increase over stock for sure!  And one of the great things about EFI is you don't have to sacrifice WOT power to do this-- my MR2 that's getting better mileage than stock on the highway, also makes more power than stock when I step on it-- it an entirely separate part of the EFI map!

That said, if tuning for emissions is your goal you actually may be able to do a better job than the factory did as well though your task will be tougher as that's at the top of the factory's priority list.  Areas you may be able to improve:  Often factory cars idle richer than 14.7:1, and under power are again richer than 14.7:1, though they may need to be depending on usage of the vehicle.  Don't lean out your tow vehicle and then try to drag your boat up a steep hill-- bad things can happen!  (Of course you could always tune a map for when you're towing, and a map for when you're not...)

Note-- You'll need to check your federal/state/local regulations on whether it's legal to modify the EMS on a street driven vehicle.

 

More on using the the MegaSquirt to tune for better fuel economy and/or emissions....

While the MegaSquirt Engine Management Systems we offer are most often installed in the pursuit of power gains, often economy or even emissions improvements are just as possible as well.  In fact due to the nature of programmable fuel injection usually you can achieve all three to some degree, power when you are on the throttle, and a blend of economy and improved emissions when you are lightly cruising around town. It’s really all in the tune. The factory will have tuned your engine to run around at 14.7:1 air/fuel ratio (AFR) when cruising and at light load. This is the ‘chemically correct’ or ‘stoicheometric’ (stoich for short) AFR which basically means this is the air/fuel mixture at which the most complete burn of the fuel will occur. It’s also the proper mixture for the catalytic converter to best be able to do it’s job, in other words, you car comes tuned from the factory for reduced emissions.

Note at wide-open-throttle (WOT), if your goal is power, you’ll be tuning a somewhat ‘richer’ mixture than this , for a naturally aspirated car this is usually in the 12.5-13:1 range under WOT. But if chasing better fuel economy while cruising you may tune somewhat leaner than 14.7:1, some say the magic number is as lean as 15.5:1, or maybe even a bit leaner when lightly cruising at highway-like speeds/loads. That can lead to quite an improvement in mileage over the factory 14.7:1 tune. Not all engines like to cruise this lean so your ‘mileage’ may vary.  Note this can also negatively effect emissions.

That said, if tuning for emissions were your goal you actually may be able to do a better job than the factory did. Often factory cars idle richer than 14.7:1, and under power are again richer than 14.7:1, though they may need to be depending on usage of the vehicle.  Ignition advance plays a key role in emissions as well, though that's another topic for another day.  Do your homework and first/foremost pay attention to your emissions laws as depending on your vehicle/state/county/etc. it may  or may not even be legal for you to play with your tune even if you're making it burn cleaner!

 

The MegaSquirt ECUs seem to have only four injector output pins (or terminals on the relay board) but they are labeled as pairs so this is even more confusing, do I have two or four injector outputs?  And how does either two or four outputs allow me to run 6, 8, or 12 injectors?

You've got two 'banks' of injectors. Or two 'groups' if you will.  You can use one or both of them. With 1-6 cylinders one is fine, though you can use both. With more than six you should probably share the load across both banks. 

Each bank has two terminals that you bring together to a nice fat (like 14ga) wire that then goes out to all of the injectors on that bank. So for an 8cyl for example you might choose to run two banks of 4 injectors each. You'll run 12v to one side of all eight injectors in the 'crank' and 'run' positions. Then you'll run the 14ga wire out from one pair of terminals (one injector bank output) nearby the injectors where you'll split that 14ga off into 4 smaller gauge (18ga probably) short wire runs to the individual injectors. Do the same thing for the other bank.

The MegaManual's 'Sensors and Wiring' section has a wiring diagram that shows an example of this for a 4cyl car. Same principle for an 8cyl or even a 12cyl. And actually for a 1-6 cyl car you can just use a single bank and run all of the injectors from there if you want to. There are different reasons and theories for doing it different ways. Here's a link to the wiring diagram I mentioned.

 

 

Is there a central place where I can download maps that others have shared?

Maps can sometimes be found on the MSEFI.COM or MSEXTRA.COM forums that are similar enough to be used as a base map for your vehicle but it’s generally not encouraged to just grab someone’s map and run with it, there are a few things to consider. You want to ensure their setup is as similar to yours as possible, and more importantly you’ll want to make sure they were running the same firmware version you are running. If not then you can copy the information from their map manually, but don’t import it into your ECU as it’s very possible some of the data won’t import properly into a different firmware version. 

Another thing to consider, especially if the ECU setup you're using required modification to control your vehicle's ignition system, is are the mods you're using identical to the mods used by the person that created the map?  Their ignition settings could be different from what you need, and could damage your coil or ignitor.  Things to watch out for are the SPARK OUTPUT setting (inverted or non) and the DWELL settings. 

The most important thing to remember is that no matter how good so-and-so told you thier map would work on your car, you are still ultimately responsible for making sure your ECU is properly setup for your car, and that your car is properly tuned.  That means looking over the maps setting BEFORE you start the car, do the ignition settings look right and does the ignition table look logical?  Is there 60 degree of timing at WOT, if so, that's probably not right....  Then when you start the car you should still treat it like you need to tune it yourself from scratch, you've just hopefully got a really good headstart.  Tune the idle first, then slow speed VE and ignition, cruise VE and ignition, and then work on up to higher loads and finally WOT VE and ignition.  Read the MegaManual cover to cover.... again....AGAIN!!!   There are good books out there on tuning as well.  This stuff is fun... but you do have to do some homework.  Best homework I've ever done though.

 

Idle Air Control valves versus Fast Idle Valves--- What does my car have and how can I tell?

Here's a way to figure it out-- on a cold morning, when you start your car it idles higher than normal right?  That's because this valve is open letting more air in to idle the car up to it warms up faster.  Now... if you sit there until it warms up, does the idle drop back down to normal all of a sudden?  If so it's a FIDLE valve (two wires, ground and 12v+).  Or does it slowly idle back down to normal a little at a time?  If so it's either a PWM or stepper motor valve.  So now you have to look at the valve.  How many wires does it have?  Generally a PWM valve will have 2 wires, sometimes 3, and a MS-2 compatible stepper motor IAC will have 4 wires (MS2 has been tested with GM and Jeep IAC valves). 

 

I'm considering converting my car from carbs to EFI-- what do I need to consider?

Starting with the fuel system it will need to be converted to a high pressure system suitable for fuel injection (around 43.5 psi for MPI, less for TBI if you go that route), if you can get a TBI unit (with TPS) that bolts to your manifold that may be the simplest route (though their may be more power in a good MPI setup), otherwise you’ll need to buy or fab up an intake manifold and throttle body with TPS, fuel rails, etc.    I don't carry the manifold and fuel system bits at this time, just the engine management systems and accessories, so I'll move on to that....

FOR FUEL AND IGNITION CONTROL-- We’d suggest running a MegaSquirt-II PCBv3 or v3.57 unit and you’ll need a compatible Crank Angle Sensor to determine engine position and RPM from as well as some way to fire the ignition—with the MS2 this is generally a distributor based solution or the Ford EDIS or GM DIS distributorless solutions which could be adapted to your engine (most adaptations use EDIS which also uses it’s own 36-1 Crank Angle wheel which can be mounted on the crank pulley).  You can read more about ignition options in the MegaManual at www.megasquirt.info in the MS2 section. 

FOR FUEL ONLY-- You could run any of the MegaSquirt ECUs, the MS1 or the MS2, PCB version doesn't matter so much, the later version are the best of course as there has been continual improvement.  Pickup up your ignition signal from the negative terminal of the coil, run your IAT, CLT, TPS, and O2 sensor inputs to the MegaSquirt, calibrate the MS to the sensors if they are not GM sensors and start tuning.

If you haven’t yet I’d suggest taking a look through the ‘MegaManual’ over at www.megasquirt.info as it will go into detail about most aspects of the conversion/installation/configuration/tuning and help to make things clearer. 

Here’s a list of what most people would commonly pick up—I’ll list what I deem as ‘required’ and then some 'recommmended' and ‘optional’ components.  Then I’ll provide a link that goes into some detail on why I made these selections and that will also help you to decide on the optional components.

 ‘Required’ 

(Note you can substitute DIY kits for the below to save some cash and learn a lot in the process)

MegaSquirt-II EMS System - SMD PCB3.57 - Assembled Unit [MS2357-C] 

MegaSquirt Stimulator - Assembled Unit   (Truthfully not required, but most who decide not to get one regret it...)

MegaSquirt Tuning Cable (DB9 Straight Thru) 

 

'Highly Recommended' 

Innovate LC-1 Digital Wideband Controller with Sensor 

12' MegaSquirt Wiring Harness (MS1 / MS2 Ready) 

 

‘Optional’

MegaSquirt Relay Board - Assembled Unit 

MegaSquirt-I Relay Cable 

GM Open Element IAT Sensor with Pigtail 

GM Closed Element CLT / IAT Sensor with Pigtail

USB to Serial Adapter - Works with MegaTune! 

  

Here’s the link I mentioned with more info on each of the above--

http://www.diyautotune.com/faq/megasquirt_what_do_I_need.htm

 

 

Where can I find the MegaSquirt Schematics?

MegaSquirt ECU PCB 2.2 Schematics   More info at http://www.bgsoflex.com/v22/msv22.html

MegaSquirt ECU PCB 3.0 Schematics     More info at http://www.megamanual.com/ms2/pcb.htm

MegaSquirt Relay and Power Board Schematics     More info at http://www.bgsoflex.com/mspower/mspower.html

 

Using the Relay Board with the PCBv3, what do terminals S1-S5 do?

This is the best way to go about this-- You can use the schematics for the PCBv3 ECU and the Relay board to trace it back. Here are the Relay Board schematics and here are the PCBv3 schematics.

Here’s the quick answer though mapping these terminals back to the corresponding pin on the PCBv3 ECU’s DB37:

S1 = 25
S2 = 27
S3 = 29
S4 = 31
S5 = 36

With the MS-I these were unused by default, available as spare inputs/outputs. With the MS-II S1-S4 are used for the stepper motor IAC, and S5 is the ignition output.

For more information on the Relay Board check out this page:  http://www.bgsoflex.com/mspower/mspower.html

Note you can do the same cross reference for the PCB2.2 ECU and the Relay Board, just use the PCB2.2 Schematics.  Though the pinout is of course the same...

 

Will the MegaSquirt work with my stock ignition system???

This is the most important thing to determine when attempting to control both fuel and spark.  In an ideal situation, you can take control of your stock ignition system and call it a day.  That is most common on distributor based vehicles.  If you're willing to do a bit of modification to the MegaSquirt in the way of adding coil drivers it makes this a valid option for many more ignition systems.  We've begun a process of documenting this rather large subject, and we're going to go ahead and make our work in progress available as what we've gotten together at this point will be helpful to many.  We'll continue to add to it and cover the various other types of ignition systems as well.

Tech Article:  Will the MegaSquirt and MegaSquirt-II work with my Stock Ignition System?

 

If you do need to adapt a different ignition system to your vehicle:

Ford EDIS is a distributorless ignition system that’s very easy to adapt to just about any internal combustion piston engine out there—you just need to mount (weld) a 36-1 trigger wheel to your crank pulley and build a bracket for the VR sensor to locate it next to the trigger wheel. That’s the hardest part and the only fab work. The rest is a bit of wiring. The EDIS system has an EDIS module and a coil pack. The module is wired to the VR sensor and the MegaSquirt, and also the coil pack. The MegaSquirt-II is what I would recommend for EDIS control and will take full control of an EDIS ignition system easily.

Here are some links with more info:

Here’s all the parts that are needed and where they can be found if you wanted to dig them up yourself:

MS1/Extra EDIS manual

Here’s the MS2 manual:  http://www.megamanual.com/ms2/index.htm  Which has an EDIS specific section at:  http://www.megamanual.com/ms2/EDIS.htm

 

Can I leave my stock ECU in place to control non-EMS related gadgetry, while letting the MegaSquirt control the engine?

Yes you can-- This is what is known as a 'Parallel Install' and on some newer cars where the OEM is putting more and more responsibility on the ECU (more than just an Engine Management role) you may need to go this route.  Some of the other responsibilities that OEM's are putting on the stock ECU are gauge control, cruise control, auto tranny lockup, etc. 


You’d basically leave the stock ECU in place, and leave the stock sensor inputs connected to it. Then you’d run a new CLT and IAT sensor for the MegaSquirt, and then share the TPS and O2 signals between the stock ECU and the MegaSquirt. You’ll disconnect the spark output(s) from the stock computer and wire the spark input to the MegaSquirt (pin24). You should be able to share that signal in most cases. Next wire the MS spark output (pin36 usually, depends on model and mods)to the stock igniter or directly to the coil if modded for direct coil control.   Then disconnect the fuel injectors from the stock ECU and wire them to the MegaSquirt. This will basically give your factory ECU control of everything but the engine, and give the MegaSquirt control of the engine.

Note that's just a quick rundown, and not necessarily in the order you might go about things.  For example, you might prefer to start with fuel control, go ahead and do all of the above EXCEPT the spark output change (you do need the spark input shared with the MS at this point).  This way you've got full fuel control, but the stock ECU is still controlling ignition.  You can dial in your fuel map and get the car running good, and then move spark over as well with this transition being much smaller than taking it all on at once.  Not to mention you'll know the MS ECU and the tuning software MUCH better.

Note some may call this 'running the MS as a piggyback' though it's not.  A piggyback ECU simply manipulates the stock sensor signals to 'trick' the stock ECU into performing differently.  There is no trickery going on with an install as described here,  this is a full standalone EMS implementation, we're just leaving the stock ECU around to control the NON-EMS stuff.  Call it a 'Parallel Install' as the two computers are working in parallel each playing their part, not tricking each other. 

 

Can I use the stock IAT and CLT sensors with the MegaSquirt?

Yes you can in almost every case-- the exception is that you sometimes remove your stock IAT sensor as it's a part of the stock MAF or AFM on many cars.  If this is the case then you'll need to add another IAT sensor to the intake tube, usually just before the throttle body, and after the intercooler if you have one.  The idea is to measure the air temp as it enters the engine.

Here's an article that shows how to measure the resistance curve of your stock (or any really) sensors so that you can input these values into MegaTune for the MS-II, or EasyTherm for the MS-I, to calibrate your ECU for your sensors.

Measuring and Calibrating your Coolant (CLT) and Intake Air Temp (IAT) sensors

 

 

Help!  I broke the pins on my MS-II Daughterboard!

The pins are Digikey Part# ED7764-ND.  We may try to order some in and carry them if needed but we don't have them at this point.

 

 

DIYAutoTune.com's MegaSquirt Assembled Units MS130-C and MS230-C

 

There are several 'optional' or 'choice required' steps during assembly of the PCBv3 MegaSquirt units, how are the DIYAutoTune ECU's configured?

The MS130-C MegaSquirt-I PCBv3.0 is by default a fuel only EFI controller running B&G's default MegaSquirt firmware.  These are configured to be triggered from the (-) negative terminal of the coil by default.  It is fairly easy to convert them to be triggered from a Hall/Optical/Points trigger if you prefer.  Here are the steps to take:
  • Cut out C12 and C30.  Don't jumper them or anything, just clip the leads and leave them out.  (Assembly steps 50h and 50d)
  • Jumper D1.  You can remove the diode first, but you don't have to.  It's easier to just solder a little lead shorting both of it's legs together.

The MS230-C MegaSquirt-II PCBv3 is by default configured for fuel and ignition control running the current release of B&G's MegaSquirt-II firmware.  These are configured to be triggered from a Hall/Optical/Points trigger by default.  The IGBT High Current Ignition Coil Driver circuitry is installed, but not jumpered to be enabled.

 

 

 

WideBand o2 / Oxygen Sensor Systems from Innovate Motorsports

 

Why is a wideband o2 sensor better for tuning AFR than a narrowband o2 sensor?  Isn't my 1/2/3/4/5 wire stock o2 sensor good enough?

A wideband o2 sensor system will give you far greater tuning ability than a narrowband sensor.  The problem with a narrowband sensor is that it is only truly accurate at 14.7:1 AFR.  The factory will have tuned your engine to run around at 14.7:1 air/fuel ratio (AFR) at cruise and light load conditions. This is the ‘chemically correct’ or ‘stoicheometric’ (stoich for short) AFR which basically means this is the air/fuel mixture at which the most complete burn of the fuel will occur. It’s also the proper mixture for the catalytic converter to best be able to do it’s job, in other words, you car comes tuned from the factory for reduced emissions and that's why that narrowband sensor is there.  Therefore it will be useful for tuning cruise Air/Fuel Ratio (AFR) only as long as you’re tuning for 14.7:1 air/fuel ratio.  However under Wide Open Throttle you’ll want to tune for somewhere between 12 and 13:1 (NA) or richer (FI) most likely and the narrowband won’t tell you anything useful at that range.  Likewise at cruise you may not want to tune for 14.7:1, maybe you want better fuel economy at cruise and you want to tune to 15.5:1 or even a bit leaner possibly. Only a wideband can give you accurate feedback outside of the stoich 14.7:1 reading that NB sensors are designed for, and allow you to tune for best power and best economy.

 

Do I have the newer or older style LC-1?  Should I get it replaced if it's older?

First...  the issue is that if there is a voltage differential or any other cause that would pull your 5v output to anything above 5v it could burn out the DAC on the older model LC-1.  Wired properly most people never had a problem with them but Innovate decided to make the circuit infinitely more robust now and provided an updated version of the product, and RMA'd any units that were damaged due to the 'issue'.  They were truly a class act in how they handled this.

The 'older model' LC-1's were up until about June 2006, in white/beige box.  The new models were sold since then and Innovate updated the packaging at about the same time to a blue/black box and later still to a white/red box.  The more definitive way is to determine which model you have is to check the serial number.  The serial for the LC-1s with the analog output fix are LC11188 forward and all LC-1s that start with CLC.  Note that in  fall 2007 Innovate started using a white/red box, still the new LC-1's just a different box design.

Bottom Line: Wiring it according to the docs is the most important thing. Not just for longevity but for accuracy as well. You don't want a voltage differential in your readings so you definitely want to ground your LC-1 at the same point as your ECU (assuming you're feeding the output back into the ECU) or datalogger if that's what you're using. Then ground the heater ground to a separate point as per the docs. This will make even the old LC-1's last forever in my experience....  See the FAQ entry below for more info on this.

 

 

How should I wire up my Innovate LC-1?

For the most part you'll follow the 'Quick Start Guide' that comes with the LC-1 to the letter.  If you lost that or need a copy of it for some reason you can download it here:  LC-1 Quick Start Guide for the LC-1 or here: LC-1/XD-1 Standalone Gauge Kit  if you have the combo kit.

Here is what we'd like to add:

  • Ground the LC-1 and the MegaSquirt together.  This is to prevent a voltage differential and will ensure accurate readings.
  • The factory EFI system's fuel pump relay often makes a good source for 12v switched power.  This is a required source for 12v, but often a good one...

 

For any LC-1 purchased after June2006, that should be all you need to be concerned with when wiring it up.

  • THIS STEP IS ONLY ON 'older model' LC-1'S as defined above (and below actually) Use a 470 ohm, 1/4watt resistor in between the analog output of the LC-1, and the o2 input of the MegaSquirt.  So you'll wire the analog output from the LC-1 to one side of the resistor, and then you'll wire the MegaSquirt 02 input to the other side of the resistor, forcing the signal to pass through it.
    • Blue Box or White/Red box LC-1's (started shipping around mid-June '06) have an updated DAC that does not require the 470 ohm resistor when used with MegaSquirt.  Another way to identify if you have this updated LC-1 that doesn't need the resistor is the serial number will be LC11188 or above, or the serial number will start with CLC on new models.

 

How should I wire up my Innovate LM-1 or LM-2?

For the most part you'll follow the 'Quick Start Guide' that comes with the LM-1 / LM-2 to the letter.  If you lost that or need a copy of it for some reason you can download it here:  LM-1 Quick Start Guide

Here is what we'd like to add:

  • If you are simply using the LCD display on the LM-1 / LM-2 to tune your car you have nothing different to do.  However, if you are routing an analog output from the LM-1 / LM-2  into the MegaSquirt you should ground the LM-1 / LM-2 and the MegaSquirt at the same point.  This is to prevent a voltage differential and will ensure accurate readings.  I've been know to clip the cig lighter connector wire that comes with the LM-1 / LM-2 and put quick disconnects on it, and install the same type of quick disconnect connectors on the MS Harness so I can pull power and ground from the same source it pulls from, ensuring the MegaSquirt gets an accurate sensor reading. 

Note-- You don't ever need the 470 ohm resistor with the LM-1.

 

How do I configure MegaTune for the Innovate LC-1 or LM-1 / LM-2?

For a long time we guided customers on how to re-program their LC-1 / LM-1 / LM-2 to output a slightly different signal from default.  The goal of this was to increase the resolution of the signal in the range of AFR most users will spend their time in.  What we had recommended was to program the output you were using to send a signal that represented a 10-20:1 AFR from 0-5v.  While in theory this is great and does increase resolution a bit, in practice it's not really needed and is probably more trouble than it's worth for most users.  The benefit of this is almost immeasurable, so going forward we recommend leaving the analog outputs on your LC-1 / LM-1 / LM-2 at their default settings.  Then to configure your MegaSquirt to talk to your LC-1 / LM-1 / LM-2 do the following:
  • First in the MegaTune Configurator you need to select Innovate Default.
  • Then in the MegaTune EGO settings select 'wideband sensor'.  Later you can come back and use the MegaManual to tune the rest of the settings on this page.
  • Lastly (and only for MS-II users, MS-I can skip this) you’ll want to go to TOOLS>Calibrate AFR Table and choose the Innovate Default setting and click OK, this will calibrate your MS2 to read the LC-1 / LM-1 / LM-2 properly.

 

 

Shipping / Customs:

 

Will you reduce the value of my order on the customs paperwork or mark it as a 'gift' so I pay less in customs duties/taxes/import fees?

We do get asked this all the time and we wish there was some way to avoid these taxes and fees for our international customers but unfortunately there isn't.  We must properly fill out all customs paperwork and include a receipt with your order.  We made a commitment early on in running our business to be 100% straightforward and honest in all of our dealings, with our customers, vendors, and even the tax-man.  We hope you understand and even find comfort in knowing that we're committed in being 100% straightforward with you as well.  We do appreciate your business and will continue to strive to keep our prices affordable.  Thanks!

 

 

 

Other FAQs

Main MegaSquirt FAQ  This is the main MegaSquirt FAQ, as well as the MegaManual.  You will do well to become one with the MegaManual.  Let it flow through you.  Use the farce!

Matt Cramer's MegaSquirt FAQs  Tons of other information Matt has gathered up.  A good addition to the Main MegaSquirt FAQ and the above!

Innovate Motorsports FAQ  Frequently Asked Questions on Innovate's Wideband Products straight from the pros at Innovate.

 

Click Here if you have questions or would like to contact us!
 

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