karter74

iTrader: (4)

Alrighty guys, I need some serious help on getting this to work on my car. I'll try to be as descriptive as possible cause I'm hoping its just something simple I'm missing.

Anyways, I've tried starting the car and it does nothing bur surge drastically. It loses RPM readings in a pulse type fashion (on-off) and in MegaTune it says "Not Synced".

I built the Megasquirt in accordance to the MSIIextra manual 4/2 CAS, but the only difference is I changed to different input pins on the DB37 (a la DIYAutotune). The only questionable thing during the build process was hearing from some people that the 1k resistor connecting to pin JS10 was unnecessary because MSII already had it (I put it anyway). For the outputs, I copied DIYAutotunes because they are identical (but using the updated 330ohm resistors instead of 1k) and copied their pin outputs.

For the software settings, everything is typical, I just used this picture for the ignition settings:



Attached is a spreadsheet of what my DB37 harness looks like. As far as I know, everything should be correct if you follow the input and outputs pins taken from DIY.

I truly hope someone can help me solve my problem, I'm banging my head against a wall right now. I appreciate any help you can give!

patsmx5

iTrader: (16)

Post your msq too and any datalogs you have taken. Also, does it run at all? Or does it crank on the starter but never fire up? Or does it run but very poorly? Be a lot more descriptive. Well focused pics of the board both sides would help too. We need more info. Right now, you said " I have a problem". To help, we'll need a lot more info. All the gauges work in megatune?

karter74

iTrader: (4)

Ok, sorry for not giving more details.

No, the car doesn't run. It cranks, starts, and surges dramatically, all the while MegaTune is pulsing the RPM readings off and on. I have now attached a log file of the event, detailed pictures of my board will come soon. Also my .MSQ file for the car.

patsmx5

iTrader: (16)

lol. Found a few problems. Just a sec.

EDIT: Your MS2E right?

patsmx5

iTrader: (16)

Where did you get this msq? You make it up or get it from AbeFM by chance?

patsmx5

iTrader: (16)

Try this.

EDIT: Are you sure the spark settings on the screenshot are right? Pretty sure those are all way off. Look them up, but I know most here run a 60-70 something trigger offset. And I'm not sure about the rest of that either.

ALSO: You only have bank one of the fuel injectors turned on. So go in and turn on the other bank and copy your setting from bank one and enter them for bank 2.

And then add some fuel to your VE table down low around idle. It's really lean.

karter74

iTrader: (4)

To give a little backstory on the car, I purchased it with MS2extra already running on it. The guy I bought it from was an EE and very smart and figured out the input and output mods himself but they don't match up with the now documented procedure. In other words, the car ran, but poorly, randomly cut out, backfired, reset, etc.

So having already built MS for my other Miata, I figured I would tear into this one, clean everything up, and build the proper ignition circuits. The MSQ is very similar to the MSQ he ran on the car (thats where I got the 7.5 offset). I can't recall at the moment, but the car wouldn't even start if I set the ignition trigger to falling edge instead of rising (its whatever the MSQ is currently set at). The screenshot provided was from the MS2extra manuals, I used it as a reference for everything except the trigger angle (used the one that the previous owner had set on the car).

My curiosity is whether it matters if the ignition input capture is set to rising or falling, since only one will actually start the car. Also, the car seems to start whether I have the spark output set to Normal or Inverted, even though I thought it would only work when set to normal (the previous owner had it set to inverted).

kday

Maybe obvious, but did you try swapping the plug wires from coil to coil?

karter74

iTrader: (4)

Attached are pictures of my board. On the optoisolator there is a SMD capacitor I'm using and another on the second MAP sensor.

To simplify things, these are the mods to the board I have performed:

Optoisolator circuit for 2nd trigger input
PWM Idle
Cooling fans using warmup LED
Second MAP sensor for barometric correction
JS0 is a programmable output I will use for the A/C WOT switch

The circuit is as follow
Spark A (D14) goes to IGN (330ohm resistor used)
Spark B (D16) goes to IAC2B (330ohm resistor used)
Cooling fans on IAC1B
Programmable output on IAC2A

MAP sensor goes to JS4 (built as per instructions)
S12C goes to JS9
Second trigger from optoisolator goes to JS10 (with .1uF cap for filtering)


I followed this MS2-Extra Miata 4g63 Manual to the letter except for the input and outputs pins since it doesn't matter.


PatsMX5, I haven't really looked around, but where do I have the option of turning on the other bank of fuel injectors?

patsmx5

iTrader: (16)

Basic setup>injector characteristics. You'll see bank two below bank one. Double check that your values for bank one are correct and then copy them to bank two.

When you did that log earlier, was it on the starter the entire time or was it running like that on it's own?

And again, double and tripple check your spark settings that you posted in the begining. I 'think' I ran inverted on mine, but not sure. But if you get that setting wrong, you'll fry your coils. If in dourbt, hook a meter to the spark outputs with the key on, engine off, coils unplugged. If it's right, you'll show 0 volts. If it's wrong, you'll see +5V all the time, which will fry your factory coils ~30 seconds.

karter74

iTrader: (4)

When I took the log, thats how the car was actually running, I jabbed the gas a couple of times later in the log, but that is how it was 'idling'.

As far as enabling Bank 2, before I ever tore into the car, the settings only had bank 1 enabled and the car ran fine so I'm not sure what I changed that would require bank 2 to be enabled, but I can give it a shot tomorrow.

Thanks for all your input so far, hopefully I'll get this problem solved quickly. If anyone else has any ideas, all input is welcome!

(I also have not tried swapping the plug wires, I'll try that too (not sure why that should work, but worth a shot)

patsmx5

iTrader: (16)

Also some of those transistors should have nylon screws and nuts as to prevent the body of the transistor from seeing ground. You should switch out the ones to nylon or at least check them with a meter. Megamanual outlines what the resistance (in megaohms) should be on which ones.

Yeah, bank 1 drives a pair of injectors and bank 2 drives the other pair. Unless you have all 4 wired into one bank, I can't see it running on 4 cylinders.

And what the hell, "and the car ran fine". You're saying you had it running fine at some point on MS2E? How long? Did you drive it? I mean, did it work for 5 months and now this or are you starting from nothing and trying to get it going? I'm confused now.

Good luck getting anyone else to chime in. They see MS2 in the title and won't even click it, much less read it, and further less offer a response. MS2'ers are few and far between. Hence why I'm helpin' ya.

karter74

iTrader: (4)

Well, I bought the car back in August and it ran 'ok'. Like it would start up and idle fine and you could drive around town, but it would randomly misfire, sometimes idle at 2200RPM, tach would blank out for a second, etc. He also had the A/C working in the car with the WOT cutoff waaaay before anyone had anything published on how to make it work. I knew the wiring for the car was a tad messy (including building the MS) so I decided to fix all these small issues. I felt the best way to fix the poorly running MSII was to 'start from scratch', IE clean up all the wires and do things properly.

The guy I bought it from was an EE and extremely intelligent. I would consider him a pioneer in using MSII(extra) as he built a working MS before any tutorials existed, so his spark input and outputs mods were slightly different than the tutorials that have become published (another reason I figured to rebuild the MS, build the proper circuits in effort to alleviate the small quirks the car had). The MS itself is fairly old and I think came with those screws (can't say for sure).

Thanks again for your support!

kday

Pretty sure you only need to set the bank 2 injector characteristics if they differ from bank one (i.e. staged). I do not have anything set for bank 2 on my MS2, and I can assure you that all injectors are firing. (Even if I've only been able to drive it about 10' due to snow :( )

karter74

iTrader: (4)

Still having some issues, I think it may be due to the loss of sync I am experiencing. Anyone else care to chime in and give me their take on it? (DIYAutotune HELP!)

patsmx5

iTrader: (16)

Is that how you have the injectors wired up? If so, you have to run bank 1 and 2.

Tell us what advice you have tried, what happened, what changed, how it's doing now, etc. I really dont' know what to tell you. Did you try everythign suggested? What affect did it have? Etc. I mean I don't know if I should tell you to turn on bank 2 for the 3rd time or if I should tell you to check your wiring.

karter74

iTrader: (4)

Alright, well I just got in from some testing. I tried swapping spark plug coils and wouldn't start (did backfire once). I attempted turning bank 2 fuel injectors on, again, no difference. Turned off idle control, nothing. Tried to change trigger angle from 7.5 to 60 and saw no difference either.

I built the opto-isolator circuits in software and both should be the same polarity (and my schematic is identical to what is installed in the car).

I'm getting extremely frustrated as I don't understand why this isn't working. The sync flashed 'synced' and 'not synced' constantly when the engine is running, losing my RPM signal in a pulse like fashion.

It is even more frustrating knowing the car ran beforehand and doesn't now. I'm extremely tempted to go to MS1 where I know I shouldn't have issues....

If anyone else can look at my log file or MSQ, I would greatly appreciate it, otherwise for the moment, I'm stumped.

patsmx5

iTrader: (16)

If you are loosing sync, your input circuits aren't right. If you did anything different from what everybody else does, now would be a good time to change it. I run MS2E but I use a different ignition setup than you or anyone else here, so I can't help you there. I tell you you need the 60-70 trigger offset. I don't know **** about MS, but I know everybody here runs 60-70 for that number.

Like I've said, oh I dunno, fourteen times, HOW ARE YOUR INJECTORS WIRED UP? Like the pic I posted? You could make a wiring diagram of how your car is wired up right now and it would probably help. Not a copy of the one I posted, but a diagram you make by tracing all your wires the way they are right now. Great way to hunt down a potential problem too.


Elaborate on the opto-isolator circuits. I don't think anyone uses those here, so why are you? Trying to play it safe?

N3v

you might want to also hit your crystal with a little bit of silicone or something before you put it back together too

karter74

iTrader: (4)

I wired my car exactly like this diagram:


The optoisolator circuits are in the instructions from the link I posted in my first post (the Miata 4/2 CAS). It just isn't working and at this point I've already ordered MS1 and plan on going that route. Non of this hassle is worth it when I can just run MS1 HiRes. While I do like the idea of good closed loop idle and boost control, I know DIYAutotune is currently working on porting it to MS1.