Microsquirt stand alone ECU installation guide

[JustinL]

I'll preface this by saying that I haven't tested all conditions with the microsquirt and as I type this I've got about 5 minutes of long term testing. For anyone who doesn't know what microsquirt is, it's a miniaturized version of the opensource Megasquirt II unit. It's advantages for our application are the dual VR inputs and low cost. More information can be found at www.microsquirt.info

Going to stand alone engine management will give you the ability to tune ignition timing and fueling. You can also ditch the air flow meter and really free up the intake. I expect power gains but that will be based on the skill of the person doing the tuning.

What you will need:
1 944
1 Microsquirt $400
2 Ballast resistors (7.5 ohm, 25 watt aluminum housed) $20
1 GM MAP sensor (I used 3bar and in retrospect should have gone smaller) $64
1 Intake Air Temp sensor $17
1 Laptop with a DB9 connector
1 Basemap (Free!)
Assorted electrical tools, heatshrink tubing, etc.




What I recommend:
Wideband O2 sensor (highly recommended)
Timing light
Scrap DME


I have used a spare DME box provided by a friendly pelicanite to use as a swappable ECU. I can switch back in my motronic just by switching the dme wiring harness back over.

This is how the box looks with the cover off:

The wires you need to connect are as follows:

Power:
DME pins 18 and 35 to AMPseal Pin 1 (red wire)

Grounds:
DME pins 16,17,19 to AMPseal 21,22,23 (Black wires)

VR sensor-
DMe pins 25,8 to AMPseal pin 33 (silver coax shield)

VR input 1+ (speed sensor)
DME pin 27 to AMPseal Pin 32 (silver coax center (White wire))

VR input 2+ (reference sensor)
DME pin 26 to AMPseal pin 4 (brown/white stripe)

VR Sensor shields:
DME pins 5,23 to DME pin 28 (ground)

Fuel Pump:
DME pin 20 to AMPseal pin 8 (purple)

Injectors:
DME pins 14,15 to Ballast resistor to AMPseal Pins 9,10 (blue and green)

Ignition:
DME Pin 1 to AMPseal Pins 11 AND 12 (White/red, White)

Coolant Temp:
DME pin 13 to AMPseal Pin 25 (Yellow)

Intake air temp and MAP sensor wire according to microsquirt.info instructions. Use 5v vref and sensor ground from AMPseal.

O2 sensor
AMPseal pin 34 to either external WBO2 or to DME pin 24

Tach (I don't have this working yet)
DME pin 21 to AMPseal Pin 35

Optional wiring

Air Flow Meter (for map/maf blending)
DME Pin 9 to AMPseal Pin 29

Idle valve (I don't have this figured out yet, but it idles fine without it)
DME pin 33 or 34 to AMPseal pin 7 (green)

Boot loader
AMPseal Pin 15 (purple) to grounding switch

Throttle position sensor (you can run without this on the n/a so this is turbo wiring)
KLR pin 21 to AMPseal pin 28 (5v vref gray wire)
KLR pin 22 to AMPseal pin 27 (sensor wire)


If you do it like me, it will look like this when wired in:




You will need to upload a basemap and here is the current version that I have (right click save as): http://www.ualberta.ca/~jlewicke/porsche944running.msq

Of course this is an install at your own risk and I don't guarantee this will work for every setup. Proceed with caution and check things as you go. Read lots about megasquirt and microsquirt. I am happy to help people with problems they may have and answer questions, so ask away!

The project thread is located here to see the trials and tribulations I had along the way. 944 MicroSquirt Plug and Play Project

JustinL

[944 boy]

Thats sweet. I may have to try that some day. Maybe when I SC my 944

[JustinL]

I just went out for a drive. It's obviously very far from a good tune. The old laptop I'm working with is pretty much toast so I just cruised around the neighborhood. Against load it bucks, but it will free rev up to around 3500 nicely (using my highly calibrated ear as I have no tach).

[JamesO]

Congrats.
Cheers for the pointers on the wiring I had a couple wrong. The porsche wiring diagram is a bit hard on the eyes.
I have found a dme pinout on frwilks site and it has two tach pins marked 11 and 21?Could 11 be the tach out? In fact the early dme connector has nothing connected to pin 21.
Trying to follow the factory manual is not fun. Cant get to my car due to injury so this is a build by drawings only in my case

[ae1969]

You are going down in the history books for this one!

Great job!



P.S First full MS2 and Microsquirt 944/951 projects are out of Edmonton. Go figure... ...

Justin, email me your msq and a log so I can look at it..... so I can help you sort out some of those running issues!

[JustinL]

Originally Posted by JamesO

Congrats.
Cheers for the pointers on the wiring I had a couple wrong. The porsche wiring diagram is a bit hard on the eyes.
I have found a dme pinout on frwilks site and it has two tach pins marked 11 and 21?Could 11 be the tach out? In fact the early dme connector has nothing connected to pin 21.
Trying to follow the factory manual is not fun. Cant get to my car due to injury so this is a build by drawings only in my case

Hmm I'll have to check my manuals about that pin for the tach. That might be the solution to getting my tach working. Thanks for the suggestion. Yeah I know what you mean about those flow diagrams!

[951Boost]

Originally Posted by ae1969

You are going down in the history books for this one!

Great job!



P.S First full MS2 and Microsquirt 944/951 projects are out of Edmonton. Go figure... ...

Indeed, you guys ROCK!!!

Thanks for pushing the envelope with the electronics on these cars and for sharing with the rest of us. I'll be looking forward to more progress reports as I want to do this to my car a bit down the road, just 'cause I like the concept of MAP over AFM/MAF and 20+ year old DME & KLR's in my view, are getting a little unreliable.

[JustinL]

Originally Posted by ae1969

You are going down in the history books for this one!

Great job!



P.S First full MS2 and Microsquirt 944/951 projects are out of Edmonton. Go figure... ...

Justin, email me your msq and a log so I can look at it..... so I can help you sort out some of those running issues!

Hey Alex, Yeah it's exciting to get things up and running. I haven't had any problems that have stumped me for more than a couple days. Hopefully things continue to go as smoothly. I've been neglecting the turbo car because of this project

My .msq is on this page if you want to download it. The old laptop you lent me finally broke that power cord. I'm going to go shopping today for a new one. I don't have any logs because I can't plug in my USB-DB9 connector on my new laptop, but hopefully I'll be able to get some tonight.

[JustinL]

I redid much of my ignition table and the car is now driveable. I definitely need a ton of tuning still. I replaced the above .msq so just re-download it if you downloaded the original.

[rdh190]

I believe glensgarage.com sells a kit for our Idle Valve. We have a 3-wire setup that I'm 98% certain is "dual-PWM" which requires 2 TIP120's plus extra circuitry. Since the Microsquirt doesn't have a Proto area I guess you'd have to build it up in the DME box.

BTW, got my MS2 daughtercard today for the conversion from MS1. Have it up and running on the Stimulator. Now the additional wiring of the VR sensors and COP's...

Thanks for paving the road.

[951Boost]

Originally Posted by rdh190

I believe glensgarage.com sells a kit for our Idle Valve. We have a 3-wire setup that I'm 98% certain is "dual-PWM" which requires 2 TIP120's plus extra circuitry. Since the Microsquirt doesn't have a Proto area I guess you'd have to build it up in the DME box.

BTW, got my MS2 daughtercard today for the conversion from MS1. Have it up and running on the Stimulator. Now the additional wiring of the VR sensors and COP's...

Thanks for paving the road.

Yeah found it here;

http://www.glensgarage.com/catalog/wire-idle-valve-driver-board-p-79.html


And some pics;




So do you guys think would work with the µsquirt?

[rdh190]

I don't see why not. The only problem is you would have to add the circuitry external of the Microsquirt. If you ran the signals needed thru the AMPseal connector into the empty DME you could do it. Not familiar with the Microsquirt- do they have many open jumpers for the harness (SPR1,2,3,4,etc...) like the V3.0 board?

[JamesO]

Justin
Still having trouble with the tach?
Ive managed to get my brother to come round and help with the clutch job (back injury).
can bolt on the exhaust (muffler?) and plug in the microsquirt and see if i get tach
if thats of help?

[JustinL]

I've shifted over to working on the turbo car for a while. It's getting a new clutch, turbo and exhaust. AE1969 is a master wrencher working with my rusty east coast car. Once that's back on the road, I'll rip into the microsquirt again.

[JamesO]

Fair enough.
will finish the clutch job first.
Hopefully my brother will help again tomorrow.

if all goes well will plug in and do some tests anyway.

[ae1969]

Originally Posted by JustinL

.......working with my rusty east coast car..

I have not eaten that much rust/dirt/oil/and miscellaneous road kill in a long time!

Now I remember why I don't do this for a living........

[Dean924s]

I am bringing this up from the dead BUT I am in the process of putting a megasquirt in my car and have found the work that Justin did invaluable. I am going with a Megasquirt 2 V3.0 running extra 2.0.1. For the ignition I am using a MAP based EDIS ignition that I adapted from a 1993 Ford escort wagon. I have it running with this system in place using the MJLJr from Autosports labs. It has been running in my car for almost 18 months with no issue. But like all projects I can not leave a perfectly good running car alone and I have wanted to do two things.

1. Get rid of the speed and reference sensors
2. Get rid of the AFM

My setup will do both while still being relatively easy to convert back to the DME and the MJLJr if I have to. (not plug and play but doable on the side of the road with a couple tools)

So I am getting to the point where I need to be thinking about maps. I have the EDIS map from the MJLJr that I am going to adapt to the MS table. Just a matter of adjusting the bins a bit (15 min work) Anyway I wanted to see what Justin was doing so I downloaded his MSQ file and brought it up in Megatune. The first thing I noticed once I put Justin's .msq file is the ignition tables seems to be written for a turbo car but it has been superimposed on the NA portion of the map (20-100 KPA). Let me try to explain.

From 20-55 kpa (the bottom half of Justin's map) it looks like a NA map (that I would recommend expanding all the way up to 100 KPA) From 60-100KPA it looks like the "in boost" part of the table from a 951 map. This should be in the 100-200KPA section of the map (that only a boosted car will have)

So getting back to jason's problem of the motor laying over at 4000 rpms makes perfect sense based on what I am seeing in the spark advance map. In other words if Justin was to modify the map and expand the 20-55 section up to the 100 KPA line I bet it would get rid of the cars apparent laying over at around 4K and it would actually work!!!

I have attached a screen clip of it for others to see. (this is Justin's map)




And what I think it should be.

[/QUOTE]

This is from my NA Ignition map thread. Note that the KPA is inverted top to bottom but as you can see the timing does not drop off like in the maps that Juston had in his MSQ file.

This is the Thread that covers all my NA ignition research and testing of the various maps (and me finding I had them typed in to the MJLJr upside down) LOL

EDIT: 2010-07-14 - To bolster my assesment of Justins Map here is a stock 951 map I got / found in another thread that I was thinking of.

Originally Posted by robm-951

86 951 stock ignition map

/EDIT

Justin, If you see this I would be interested if you ever got back to the NA car? I think I may have found the answer as to why it was not accelerating past 3-4K. It always bugged me that the fuel part worked where as the Ignition did not. If the sensors were wigging out the Microsquirts VR circuits I think the Fueling would have failed but it seemed that was a success so maybe correcting the timing table (I would do it and re post the MSQ file if you want) would make your original plan of a P&P microsquirt in the 944 work after all.

[sausagehacker]

Dean and Justin how are the cars running now? Would love to get a MS community going on here.

[MACHINEMON]

I am starting a MSIII soon. I am at the trigger wheel mounting stage. I bought this one already assembled so it should go well. I agree about starting a MS community. Count me in! Joel

[Dr DIY]

Considering a MS for my current 944 rip and rebuild. Would love to keep up on any info.