How can I tell what mods it has?

All I know about it is, it's an MS1 chip (was advertised as MS2, but it's a single chip, not a daughterboard) and a v3 board, and it is modified to work with an FC.

And, it was previously used by somebody, but it's been through several peoples' hands before it got to me, so its parentage is unknown.

I understand there are several ways that an MS unit can be set up for controlling an FC.

I'm currently set up for distributor (fuel only) and standard (GM) temp senders. I'd like to not have to hunt down a Mazda air temp sender, but if I have to, then I'd rather do that then re-mod the board.

My main concern is what kind of CAS the thing is set up for: stock or modified. Also, there seem to be a few different ways of doing trailing ignition, I'd prefer to not have to use the stock trailing coil one fire/one switch arrangement in favor of having separate T1/T2 outputs, given as I don't actually *have* any FC coils. (Plus, to get things running, I'd just use my existing MSD to only drive the leading plugs - I imagine this won't be a problem)

ALSO: Would I be able to use a high-res code variant? I don't mind losing PWM, all of my quad injectors are high impedance.

 

will you be at the sept det SCCA rallyX? I can take a look at it then

 

No, I will not. Waaay too much thrashing going on, trying to get ready for the National at OVR.

There's definitely no added VR conditioner, and it looks sorta-kinda like error's setup, only not. Plus, there are more additional wires.

 

No 2nd VR conditioner means its most likely for a modified CAS with a ground off tooth. Extra wires running from the legs of one of the resistors near the LEDs or LED's themselves are for driving the stock 2nd gen or 3rd gen coils, but you can set them up to run a single coil wasted spark for leading, and individual coils for each trailing with FD mode IIRC, and that should use the same outputs. Any extra wires, i dunno. Maybe you can upload a picture of the board?

 

I finally got my camera and the MS in the same room. (Let's see if I remember to take it back to work!)

Mega-res pics available if anyone wants. Incidentally, if the person who built this remembers it, I'd like to know a few more things about it.

 

More info here, maybe this will help somebody else if they buy a "mystery box".

Went to computer shop today and picked up a USB to serial adapter ($16!), a pack of alligator cables ($6), a hard drive power supply Y-connector ($3), and an RJ45 to DB25 adapter that was not pinned yet - this is my supply of loose jumper wires to plug onto the DB39.

While installing the USB-serial adapter (I found they all work just fine as long as you disable 16550 read/write caching), I extracted the wires from the RJ45-DB25, found a wiring diagram and plugged a black wire into pin 11 and a red one into pin 28. My power and ground. Next, I plugged one end of the Y into a standalone HDD-to-USB adapter I have, found the 12v and 0v pins (yellow and black), and used alligators to connect power and ground to the MS box. LEDs light up! Still showing 12.50v at the leads, so I'm not overpowering the little dinky power supply I've got.

By this time the USB-serial adapter is working, so I can move to Step 2: Communication! i figure if I can access the settings I can maybe see how the fuel and spark outputs were arranged software-wise, so I can backtrace to where the different ignition outputs are.

So, fire up MegaTune, select my "generic unknown" car (car2 in my case), and... MT locks up and shuts down. Start up Port Checker and find this:

Confirming that it's MS1 (MS2 would have been 115200), and I need MS/Extra 029q loaded in MegaTune for communication. So, I wander over to here and look in the stickies at the top of the forum, only to find that all reference to MegaTune has been 1984'd. Looks like I'll have tio go it on my own here, since I've tried TunerStudio and the ergonomics are just all wrong to me, it doesn't flow like MegaTune does. That's personal opinion, and probably means that I'll just have to live with never using MS3.

The stopping point now is finding an 029q ini for MegaTune. I'm finding a lot of people needing it and not a lot of places to download it.

 

Forging ahead with TunerStudio and hoping it doesn't throw up all over the chip like it did on my car's chip (hooray for tune backups!) since it appears to be the only game in town for this version of firmware, without a thorough scouring of places I don't yet know where to look.

Even as I type, as soon as I have it running, I am having serious difficulties with typing - keys either dhing orrrrrrrrrrrrrrrrrr repeat (likeeeeeeeeeeeeeeeeeethat) and it goes away when I shut it off. Must... find... ini!

 

It was hi-larious when I tried to open up the tuning applets. My computer really hated that...

I realized that the firmwares were released as (code).zip so I did a quick search for 029q.zip and one of my favorite sites had it:

http://www.spitfireefi.com/downloads.shtml

They do a lot of VW stuff. I have been doing a lot of VW stuff. My VW's turbo engine will start out on the factory CIS-Lambda-on-steroids but will eventually be 'squirted along with the Mazda. Not too many standalones that will inexpensively do anything coil on plug five-cylinder out there...

Since I couldn't do any screen grabs in TS, I manually wrote everything down in my notebook. Well, I can access it anywhere now, at any rate. (No, I didn't write any maps down, that's a little over the top) Also, writing it out helps it make sense, when you read something and write it down it seems to make an intermediate step through the "make sense" portion of the brain.

I never saw a writeup for a 12-1 modded CAS setup (and the settings confirm 12 teeth with one missing, no input) but after a little reading on the MSextra site's wheel decoder page, it makes sense. The 1-3-7-9 (position A, position A return, pos B, pos B return) means that, say, tooth number 1 is the earliest that rotor 1 can fire and position A return (tooth 3 in this case) is the latest that it can fire. Likewise, 7 and 9 passing the sensor mark the earliest and latest that rotor 2 can fire. In the spark settings table, cranking timing is on "trigger return" and cranking advance angle is "0" - when cranking, the spark output occurs upon trigger return, which is 0.

So, I rotate the engine to 0 degrees on the front rotor, and put the CAS at the 3rd tooth after the blank one, because trigger return for rotor 1 is 3.

It makes sense when looked at, not so much when just reading stuff on forums.

Now, I already see a bunch of problems with the code - baro correction is turned on, which is bad if you ever suffer a reset while the engine is running. Oh, look, there's a setting for minimum and maximum acceptable baro, to prevent such an occurence... and they are set for 208kpa and 28, respectively. That covers about three miles below sea level to way over the top of Mt. Everest. I don't think I even see 28kpa with closed throttle at high RPM. This is a recipe for disaster if there ever was one. (I've always run with baro correction off)

Also, it appears to be set up for staged injection on FC N/A injectors, but the staging appears to come on-line at 1000rpm.

I don't understand the idle settings at all, which is fine since I won't be using them.

The docs also say that rotary ignition needs to be set inverted, but this isn't. Needs more investigation.

 

So I deciphered most of the mess of wires. More questions than answers.

I mapped out the wires hanging around between JS0, JS2, IAC2A and IAC1A. (Ignition outputs go to SPR pins) I won't post a pic of the diagram because it kind of grew and needs cleaned up. Cross-referenced to the MS3 board docs on the Bowling and Grippo site, and Aaron Cake's sweet FAQ.

The nutshell: IAC2A is arranged to be a grounded whatever-driver for JS0. Nice, because the .msq has JS0 controlling the fan. Simple, right.

Now, the part that made it too confusing: IAC1A is connected to that transistor's base.

Further confusion: There's another 2N5000 in the proto area with its base connected to JS2. All well and good, but its collector sharing the first transistor's ground path, and its emitter is connected to nothing at all. (I didn't mix up collectors and emitters here)

I think I see what happened.

Again, one of those things that didn't make sense until it got traced out.

JS11 has a 2.2k pullup resistor and is connected to SPR2. Clutch input? My current switch gives power, not ground, but this is easily dealt with.

Now, I'd like to know why IAC1B is jumpered to pin 30...

 

And why is JS8 grounded to XG2? I want to use JS8! I can't seem to find a reason why anyone would do that...

 

Glad you found the right ini file to look at the settings, that'll hopefully help determine what the previous person had tried to set it up to do.

Are you asking whether the ignition input should be inverted, or the output should be going low vs going high? The input is jumpered from VRoutinv to Tsel, so that inverts the tach input signal from the VR sensor in the hardware.

IAC1A, IAC1B, IAC2A & IAC2B are all basically spare pins that you can use to pass signals in and out; same as spr1-4.

So, as you said, IAC2A is the driver for a relay or something for an electric fan, switched by JS0, but the transistor base is run to IAC2A there too... maybe the PO had put in a manual switch that could allow them to turn on the fans, that was hooked up to IAC2A? Just grasping for straws here.

The other transistor looks like it was part of a circuit that never got finished; maybe for a shift light or something.

Are you sure that IAC1B is on pin 30? It's usually connected (via a trace in the board) to pin 29 (or maybe 27, i don't remember), but definitely not 30. 30 is for an idle valve. If the trace broke, I could see the use of the jumper, but otherwise...?

You've pretty-much got the idea behind the tooth settings. The position A & position B are basically the teeth that the MS knows exactly where the engine is, and therefore they are the teeth that it uses to calculate when to fire spark output A & B. Therefore, as you said, you can't fire the spark for those teeth before those teeth pass the sensor.

However, the return positions do not signal the latest that you can fire the spark. They can be used to fire the sparks when cranking, and should be very close to TDC. Basically, when the engine is cranking, its moving slowly, and is not staying very constant. Therefore, teeth take a while to pass the sensor, and in between each tooth, the engine can change speed quite a bit, making the MS's best guess at where the engine is at any given time much less accurate. By specifying that the spark will always fire as soon as that return tooth is seen, you basically are avoiding the need to guess the engine position, and instead just firing at a specific position.

 

IAC1B is indeed jumpered to pin 30. Or rather, it is jumpered to the end of D8 that traces to pin 30.

I don't know if this was intentional or error... and at any rate, since I won't be using idle control, it's immaterial, but it'd be nice to know why.

I figured the different VRouts were why the signal was not inverted in the software. Nice to see confirmation.

Now I *really* get how the trigger wheel encoding works. I may end up not using a modded CAS and instead use a 36-1. (There's a really nice one behind the timing cover of Mod V8s) Knowing fully how it works will help set it up immensely.

I am guessing here as far as the JS2/JS0 situation is concerned that the mystery wire got soldered to the wrong spot. (I don't think I mentioned - in the software, JS2 is supposed to control a shift light, which was enabled as an option) I can fix that easily enough Manual engaging a fan is trivial, especially if it is already ground side switched - just add a ground.

I still don't get why JS8 is hard-grounded. I mean, I am assuming that it's an error, but what was trying to be accomplished with it? I want to use it to make a sequential shift light with a twist - the primary (green) light comes on when the engine is in the powerband. No lights on means downshift. No tach needed!

 

Is the trace between the end of D8 & pin 30 intact? if it is, then I'd just desolder the wire from IAC1B, just to avoid trouble later. It definitely looks like there were a couple mistakes made with the modifications to that board. I'd remove those JS0 & JS2 circuits, or at least any wires connecting them to elsewhere, just to make troubleshooting easier down the line. Same for the JS8 one; I can't think of any reason it would be there.

 

I'll keep looking into it, that's for sure.

I'm currently planning on adding another coil driver circuit and running four Delphi coils in "RX-8 mode". The more I think about it, the more I don't like the idea of a waste spark coil on an engine that normally requires one spark per revolution. At 7500rpm, waste spark only allows 4ms between ignition events, that's cutting it kinda close, you know?

 

Dwell on the stock coils is 3.5 to 4 ms at the upper end of things, so at a constant 7500 they'll be running almost constantly, but since they're discharging so much (and you'll never just be sitting at 7500 all day), its still pretty safe. Plus, the plug that is firing as "wasted" doesn't take much energy to ionize the air since its at comparatively low pressure & temp, so you should be safe. Which Delphi coils will you be using? I know the stock system is pretty robust.

 

I'm not worried about cooking the coils, just having sufficient time to charge it. When you run out of time, spark energy decreases. Paying attention to the Audi guys trying to keep high power 5cyl engines alive has really tuned me to the idea of coil on plug. For some reason the fives are really sensitive to spark energy at decent power levels.

You're right, I wouldn't be sitting at 7500 all day... when the good engine goes back together, it sits at 8500-9000 for a while. I'm also picking up even more bits for the on-again, off-again blower project (main problem: where to PUT the thing) which won't see stratospheric RPM but strong spark is a necessity.

"Delphi coils" = the coil near plug application on late model GM V8s. There's two different styles, one with the connector on the spark output side and one with the connector on opposite sides. Still deciding which way would work best. But, they're fairly inexpensive - I can buy new ones for about $30 each. Junkyards sell the whole rack for $130-150.

 

Thats because they are a shitiful design and sometimes the spark find it easier to jump leads and light the wrong plug. There is a pair of neighboring cylinders which are at very wrong positions for this misfire / spark jump to happen.

Peejay just letting you know I have never had any of the non-standard rotary features work. I had attempted to implement a COP setup years ago. It became apparent everyone was using standard FC coils. From what I understand there where bugs in the code, or the configuration which stopped the coil outputs from behaving correctly. Something to do with not using the 'Normal / going low spark output' and also having rotary mode enabled.

Basically crazy **** happened and either the ignition system would 100% not work, or the coil driver (VB921 at the time) would fire the coil 1 million times per second (no exageration :P) with the ignition on the and engine not even running.

 

Yea, the power will go down if you limit the charge time, but the charge time should only be 3.5 to 4 ms anyway, and at those times you'll have a plenty powerful spark. I know the LS1 and on coils are pretty good, but I've never actually seen a comparison stock for stock vs the FC's. However, whenever the LS guys start boosting, they tend to replace the coils too... so whether the coils have enough energy to deal with the denser charge, or if this is unnecessary parts swapping by them, I don't know.

 

You are not alone with that view. I am/was really excited to use MS3 but no way am I going to use tuner studio and MS3 over MS2extra with Megatune.

 

I thought the same thing about TS, but it really wasn't hard to get used to when I went with MS2 extra with the latest release. Its functionality is the same, just the different menus are in different places

 

The main thing is TS is that the colors/fonts are difficult for me to read. Petty, maybe, but software needs to be usable, and a user that can't make out what is going on at a rapid glance cannot use the software effectively. The processor intensive tuning screens and scribble-all-over-the-tuning coding are just a nice bonus. Maybe TS assumes that anybody who uses the B&G basic code needs to upgrade to expanded firmware because they aren't cool enough, or something, so it is important to wreck their tuning work.

I've seen 1000hp engines using the stock coils. Also 1000hp V6 engines using stock (DIS) coils. Say what you will about their other designs, General Motors has really got their act together with regards to ignition systems. (Heck, the spark-making part of the HEI system worked extremely well too) "Upgrades" to GM ignition systems are a little like cone air filters... don't make any more power over the stock airbox, but it makes it look like they did something to the car when the hood is open.

 

Fair enough on the coils, I don't have any direct experience with them, just from secondary sources.

 

Pretty sure this was my original MS. I'll take a better look later.

Edit, yes it is. Wow, never thought I'd see that thing again. Lol.

I'll go through and try and remember what all I did to it, but basics off the top of my head:
I did have the rad fan output setup, but never used it.
It was setup for launch control, and used plenty.
I believe I had an output set for running the aux ports electronically (via vacuum, and a solenoid) but I never hooked that up either.

 

I found the reason for the VR not being inverted: https://www.rx7club.com/showpost.php...2&postcount=12

Just curious, did you buy that from a guy named Adam? And if so, did her have it installed on his car? When I sold it to Adam, I included all the (crappy) drawings I had about pinouts and such, as well as the harness I made. (also fairly crappy, but it worked well)

As far as the outputs, JS0 was fan control, JS2 was intended to be aux ports, JS11 is launch, and as far as XG2-JS8 your guess is as good as mine.

*the JS8 jumper I believe was to allow the use of a shift light. XG2 IIRC runs to the IAC pin which is then jumped to pin 30 of the db37, but that's just a guess.