E28 Megasquirt FAQ

[gazm3]

Megasquirt has an Alpha-N mode that uses a throttle position sensor for load calculation and the newer firmwares seem to have an ITB mode but I'm not sure how it differs. You might try asking over on the msextra.com forums, or reading the docs there.

As for plug and play, all the boxes that drop in in place of the motronic ECU that I've seen use the 55 pin connector since those motors have the 60-2 crank wheel. Some people seems to have figured out how to use the speed and reference sensors in the bellhousing with megasquirt, but that seems to be more effort than just swapping the harness since it's much more well supported in the end.

Cheers for this.

I have a euro M635csi, which I've been upgrading, now suspension, brakes, dogleg box, and 3.45:1 diff are all done, its time to get some modern drivablity out of the M88/3 with some headroom to upgrade in the future.

It seems the Megaquirt here is very popular and works well on the M30. The M88 is very similar in electronic architecture, but there seems to be a database of 0 when it comes to people talking about their Megasquirt upgrade - Hopefully that will change to 1.

I'm struggling to get a copy of the pinouts for the euro M635csi 055 Bosch ecu (mine is from 12/84). I managed to look at the 1987 M6 electronic troubleshooting manual, but its probably for the USA version Bosch 079, as it has a narrowband sensor, which I don't have, but the pinouts would be pretty close. I also cross refrerenced against the 1984 DME in a std 635csi, and aside from the barometric sensor in different location, the pinouts are the same.

It looks pretty basic, but as I have little experience with electronics construction, it would probably be wise for someone to build the Megasquirt. A chap called Peter Florence seems to come up here on this thread often, so this may be a good starting point, once I can confirm the pinout of the 055 DME.

Its running fairly sweetly on the standard computer (with Fritz Bitz chip) as I have a small device I can interrupt the fuel signal from the air meter, and alter it (with the help of the wideband sensor and A/F gauge), and upping the fuel pressure slightly and trimming the fuel out seems to add much needed timing, and has helped with dirvability and fuel economy enormously.

Still the airflow meter will act as a restriction, especially once I start playing with cams, and I will also have freedom upgrade or delete the intake plenum.

I may start a thread in the M5 section for the pinouts

[Jelmer538i]

I want to Microsquirt my S38B38 and a friend of mine is going to help me with this, he installed a Microsquirt last week on a Subaru Impreza turbo with succes. He also did my brothers S38B36 turbo (DTA Pro-8) and a lot of Megasquirts on various engines.

He asked me what kind of coils are used on my B38. He needs to know if the Microsquirt can drive them direct or if the need a resistor or somithing? (I not formiliar with this a all so It can e something elso to )

Also, does anyone know where I could find a base map from a S38/M88?

[mitch5]

so i just recieved my ms2 v3 and am stilling trying to decide what to do about the iacv, brad you should update the sticky because currently glensgarage is now a check/moneyorder only scam. I am trying to figure out where to buy an adapter board, i sent goathumper a pm but no reply. I have heard the other option is to find a 2 wire iacv. whats the best route for this?

[Brad D.]

so i just recieved my ms2 v3 and am stilling trying to decide what to do about the iacv, brad you should update the sticky because currently glensgarage is now a check/moneyorder only scam. I am trying to figure out where to buy an adapter board, i sent goathumper a pm but no reply. I have heard the other option is to find a 2 wire iacv. whats the best route for this?

It's a shame to hear that as it was a pretty sweet board that just worked and made waste spark really easy to wire up. It would be pretty easy to proto the circuit required, but I did find this as a modifiable "store bought" solution.

http://www.diyautotune.com/diysotm/zeal_3_wire_iac.html

[mitch5]

so i just recieved my ms2 v3 and am stilling trying to decide what to do about the iacv, brad you should update the sticky because currently glensgarage is now a check/moneyorder only scam. I am trying to figure out where to buy an adapter board, i sent goathumper a pm but no reply. I have heard the other option is to find a 2 wire iacv. whats the best route for this?

It's a shame to hear that as it was a pretty sweet board that just worked and made waste spark really easy to wire up. It would be pretty easy to proto the circuit required, but I did find this as a modifiable "store bought" solution.

http://www.diyautotune.com/diysotm/zeal_3_wire_iac.html

I have heard the proto area was a pain I'm the ass but I'll explore that option. Thanks for the link though that looks like a possible solution.

When I was reading through this thread though someone mentioned this http://www.diyautotune.com/catalog/pcbv ... p-134.html.
Is this a better option? Or will it work. Since the zeal motherboard is 35 bucks.

[mitch5]

so i just recieved my ms2 v3 and am stilling trying to decide what to do about the iacv, brad you should update the sticky because currently glensgarage is now a check/moneyorder only scam. I am trying to figure out where to buy an adapter board, i sent goathumper a pm but no reply. I have heard the other option is to find a 2 wire iacv. whats the best route for this?

It's a shame to hear that as it was a pretty sweet board that just worked and made waste spark really easy to wire up. It would be pretty easy to proto the circuit required, but I did find this as a modifiable "store bought" solution.

http://www.diyautotune.com/diysotm/zeal_3_wire_iac.html

I have heard the proto area was a pain I'm the ass but I'll explore that option. Thanks for the link though that looks like a possible solution.

When I was reading through this thread though someone mentioned this http://www.diyautotune.com/catalog/pcbv ... p-134.html.
Is this a better option? Or will it work. Since the zeal motherboard is 35 bucks.

[quasi]

+ on updating the sticky..

i just went straight to the gg website after reading the sticky and tried to purchase the board
I thought the purchase went though so i started building my board in preparation to install it..
I called him today and found out i have to send a check in the mail so i decided not to with there board.
So i purchased TIP120 'Mod-Kit from Diyauto because the zeal board was more expensive.It did sound like a better option tho.

so ill be waiting for that to come in then desoldering some joints and ill update my progress soon..

ill have to run a 2 wire valve if i go this route tho wont i ?. or can i still use my stock 3 wire..

Sorry might be a stupid question im still trying to figure it all out iv only barely gotten to
Input Section Construction & Testing

[Owndapwn]

Have to say, I enjoyed reading the thread, as well as a (Small, but growing) bundle of related documents.
Perhaps when I get my head in the shop, I'll start ordering pieces. Problem is, I could probably solder the whole thing together in about four hours if no one bothers me. Which is not near enough time for the head rebuild to be done.
It is, however, plenty of time to get the pigtail wired up (Already pulled the 35pin plug from my dead ECU. Honestly thinking about grabbing the 24" pigtail and wiring it now just to commit), test what I can in the stim, and read those three books on tuning.
Just curious how much you guys got your 60-2 and VR for? For my projects spreadsheet.
Based on what I'm reading, I'll be running EFI Analytics TunerStudio+, likely on Ubuntu 15.04.
That said, what can I do to get rid of my defective AFM on my fully stock B34 while I'm at it? Sort of a DIY MAF conversion involving some ABS pipe and a metal bit, perhaps? EDIT: E36 MAF can be wired up and tuned.

[Jelmer538i]

Anyone on here with a good startup tune for a M50?

[Sam Kruse]

I am inquiring about the megasquirt plug and play unit. What is the cost of it and are there additional parts needed to hook it up to a 1988 535IS E28. Thanks, Sam

[bk_856er]

I'm thinking of wading into the MS waters with my '85 E24.

Any reason not to use the diyPNP-55 unit from diyautotune? It's a Microsquirt module on a dedicated mainboard. Supports the OE 55-pin connector, 3-wire ICV and high-current ignition. Operates on MS2/E firmware. Nice integration of features. A bit spendy perhaps.

BK

[Owndapwn]

It looks like it's meant for the E34 to me, which means Motronic 1.3, so it wouldn't really be PNP. You'd still need the 60-2 and TPS and all that. So you'd really be paying $230 for a $20 PWM and a $50 pigtail with all the same hassle as the regular kit. Other than that, it's the same thing you'd be building for $350 or so.

[bk_856er]

The diy version of the PNP (diyPNP) is $430. Adding up the MSII and pigtail and misc I get $349, but I do see your point - you pay for the convenience and the additional features go unutilized in this application. But apart from the extra $$ it seems like a solid way to go? I definitely don't want (am not capable!) of blazing any new trails here.

BK

[Owndapwn]

It's functionally the same thing, it looks like. The only upside is you don't need to source a stock plug from an OEM ECU. I had an extra from when my original 059 basically melted, so pigtail is a no brainer, but if you figure the cost of a broken ECU with that plug is probably somewhere around $20-30, shipped, plus you have to remove it from the board (Depending on your soldering experience, may damage the plug. I've been soldering forever and used a pretty well stocked solder station and it was still kind of a pain. Large surface area. I didn't use a normal iron. I used a solder air gun, quickchip, and removal alloy. Total cost of equipment and materials is just under $2000), you might only be off by $50, which is the standard labor rate I'd charge at the shop to remove that plug.
It looks to me like it's the exact configuration in this write up, only neatly packaged in its own box. If you aren't super okay with soldering up the pigtail, which can be a PITA and take a lot of solder, go for the PNP.
PCB soldering, like this at least, can be done with a $20 Harbor Freight iron with a good tip and a steady hand, as long as you're using good solder and good flux.

tl;dr If ya suck, get the PNP. Going at it the long way and fucking up is going to cost more than going PNP and getting it right.

[mitch5]

After my megasquirt experience I highly recommend buying a built unit of goatthumper or someone like that. It's worth the 200 extra dollars to get a tested working board. You can try building it yourself but if unless you are really good with circuits, you will be screwed if you run into any issues like solder bridges etc. I probably spent 100 hours on my mine building and testing it, then learning about circuits so I could fix it.

[Xenocide]

I'd advise that you avoid the goathumper boards unless you're buying a built and working unit or you're willing to put up with some bullshit. I've had to hack mine up pretty good to make it work the way I want, and I'm still not done. documentation is piss poor and there are multiple revs with their own unique pitfalls.

I'm seriously thinking I'm just going to lay out a new board for myself*


*relevant xkcd

[bk_856er]

Not worried about the building part. I have extensive soldering/rework/assembly experience and my garage bench is well equipped with top of the line soldering and desoldering equipment, oscilloscopes and even a reflow oven. Would plan to do the jimstim for benchtesting regardless of MS type. Sounds like the diyPNP is a reasonable path forward for me, but kinda nervous that I don't hear much about it - not looking to blaze any trails.

BK

[Owndapwn]

On things like this, especially when dealing with services over the internet, you have to wonder how bad you really have to be to do a worse job than someone who doesn't give a shit. He just needs it to outlast the warranty. You need it to outlast software support for the tuning program. From my perspective, soldering isn't hard. It's frustrating. You sit in one place for hours and hours covered in sticky flux while lead smoke burns your eyes and nose while you stare at tiny components through a microscope and have to triple check the markings on every component, then triple check the positioning in the board, doubt the translation of the documentation, solder it in, check the joint, touch up the joint because its crooked, trim the excess wire from the piece, clean the flux, and then check it again and make sure it's not cold. Not a lot to it, but when you have ten thousand of those to do, you start to get anxious after about a hundred if not everything is absolutely perfect, then you mess with your chair or the work bench until you can crank out another thousand or so, and then you have to stop because you just wished horrible, unspeakable acts on an electrolytic because you burned yourself.
If you can find someone who does a good job at that for a couple of bills, that's not expressly a bad option. You just have to find that person who will do a good job.

bk, if you do go with the PNP kit, be sure to keep us updated on how it goes for you.

[mitch5]

I meant to use goatthumper as an example, DIY autotune will build you a custom unit and warranty it. I emailed them and they shot me a price but I'm cheap. Sounds like you know what you are doing though. I wouldn't go the pnp route though. I would go where there is the most info and knowledge. That is with using a ms2 v3.0, all the modifications on that board like idle control and wasted spark are documented. Not to mention you can buy everything including stim for like 400 bucks

[BuzzBomb]

You guys are insane. Glen's Garage is one of the original providers of MS. He's scaled it all down to just a little side business, and now just accepts personal checks or money orders because he wants to keep costs down. It's not a scam, never was. Why not just call the guy and talk to him before assuming he's just out there ripping people off? He has a wealth of knowledge and happily answered questions about my assembly concerns. Seriously. You kids and your paranoia.

[mitch5]

You guys are insane. Glen's Garage is one of the original providers of MS. He's scaled it all down to just a little side business, and now just accepts personal checks or money orders because he wants to keep costs down. It's not a scam, never was. Why not just call the guy and talk to him before assuming he's just out there ripping people off? He has a wealth of knowledge and happily answered questions about my assembly concerns. Seriously. You kids and your paranoia.

there is a whole thread on msextra forums on how he has gone AWOL, I tried contacting him and nothing. I would have loved to use one of his boards. I didn't personally try to pay but that was because he didn't respond to multiple emails.

[BuzzBomb]

Ok so I think I gave too much credit to Glen Hoag. I've spoke to him twice, seemed normal on the phone, but nothing received and no response to e-mails.
So, I take everything I said back about considering Glen's Garage for anything. Now I have to cancel two checks that still haven't shown as cashed.

[Kyle in NO]

Hands down, Peter Florance at PFTuning. You won't be sorry.

[wkohler]

Hands down, Peter Florance at PFTuning. You won't be sorry.

He's also a member of the community!

[bk_856er]

I tried to contact PF through his website a few weeks ago about engaging his services. I got the automated confirmation, but otherwise never heard back. Maybe just vacation season. Sounds like I should try again. As far as I can tell that's the only way customers can get in touch.

BK

[BuzzBomb]

People say Peter is the guru to seek out, but like you, I reached out to him a while back and he never responded. Now that GG is clearly a pile of horse shit, I guess I'll keep trying Peter or maybe get the board offered on the DIY site. Sorry for saying that any of you were paranoid. Should have listened.

[BuzzBomb]

Anyway, it's not a complicated circuit, but has anyone just built the 3 wire ICV adapter in the proto area? What are most people doing?

[mitch5]

Anyway, it's not a complicated circuit, but has anyone just built the 3 wire ICV adapter in the proto area? What are most people doing?

most people including myself, are using the diyautotunee tune pwm kit. It comes with an extra driver, the only additional piece you need is a 50watt 50ohm resistor in series with the ground.

[Lurker27]

You can also use a 2 Wire IAC without additional boards with a v3.57 - The mid 90s VW bosch model (Mine's from a jetta) works and might even use the same hoses.

I've been trying to swap to ms3 so i can get traction control working, but it's been a nightmare. Any help would be appreciated.

http://www.msextra.com/forums/viewtopic ... 31&t=60256

[BuzzBomb]

What do people do to add the shielded cable from the b35 crank sensor into a from scratch harness? Do people cut the cable before the large plug at the original location b35 injector box and add it to the new harness at that point, or is the large plug connection kept and the shielded cable pulled from the b35 up to the dme plug? I guess the question is, should the ability to unplug the sensor be kept or gotten rid of for a cleaner install? How important is keeping the shield on the cable all the way to the relay board?