MS2 3.57 help with modifications before install
 

Alright, I just got my ms2 3.57 and I'm trying to figure what modifications need to/should be done before I start wiring it up. The car/harness is a 91, and the engine/TPS/IAC are 94/95. I've found some contradicting information, though a lot of what I've read has been for the 3.0 board, but from the searching I've done this is what I think needs to be done:

JP1 (tach input selection) needs to be jumped between 2 and 3 to be set to opto-isolator Hall tach input
J1 (tach selection) jump between 1 and 2 to enable the opto-isolator
XG1 and XG2 jumped
To eliminate noise a .1 microfarad capacitor gets installed between JS8 and GND
D1 and D2 need to be jumped? not sure what this does so idk if it needs to be done on the 3.57 board

For the above, I've also read that the tach selections should be set up for VR, not to jump XG1 and XG2, and then turn the screws on r52 and r56 counter-clockwise 5-6 turns. So I'm a little confused as to which is correct.

This leads me to believe that no internal modifications need to be performed for the fuel pump, just take the purple #37 wire from the DB37 and wire it to pin 2O at the stock harness. Correct me if I'm wrong.

I've read that the 1k ohm resistors for the spark output have already been added into the 3.57 board, but it would be better if they were replaced with 330 ohm resistors, and even better if a pair of 2N2222 transistors were added. If I did want to add the transistors, are all the pin numbers the same as with the 3.0 board? Should anything be done differently since I'm installing 1zzfe coils?

In case it isn't obvious, I have no experience with circuit boards and my head hurts from trying to figure this out. Help is greatly appreciated and much needed!

I will seriously paypal $20 to whoever can walk me through this step by step. I just want to tune and drive my car not stare at wiring diagrams pretending like I know what I'm looking at.

Whomever sold you the MS2 should be able to answer your questions. Try sending an email to their tech support. I know when I had questions about building my diypnp I just sent DIYAutotune and email and they answered it during their regular business hours.

And yes, most people agree that it is confusing and sometimes contradictory looking through all of the available manuals online.

I did send a PM, I was directed to a link which showed the spark output settings for different coil set-ups, this was not really helpful since that info is about the only part I've been able to figure out with any sort of certainty (though which pins of the board the transistors hook up to is still a mystery). I did a engine swap in a weekend but have been stuck on this stupid MS for 2+ weeks. I really regret not just buying a PNP MS knowing now that I would be receiving 0 support.

I could probably figure it out on my own if someone could at least point out what differences there are between the 3.0 and 3.57 boards. Do I need to do anything to control the fuel pump or not? Do I need to do anything to control the fans or not? What does jumping D1 and D2 together do?

Out of curiosity, who did you buy it from? Like I said, I had some basic questions answered by DIYAutotune when I built my diypnp. I have asked them a bunch of questions since and they have always taken the time to respond with a definitive answer.

I bought it direct from DIYautotune. I'll try sending them an e-mail, thanks!

Our Miata install guide needs some updating. I haven't been able to get everything that we've learned about Miata installs crammed into it today, but I've just added a lot of new info to it, including how to use the V3.57 board. 6strngs, let me know if you have any questions that it doesn't answer.

I'll see if I can get some other improvements covered there as time allows.

Just read through it, awesome information Matt! It's laid out very clear so even :noob:s like me can understand. Thank you so much! I was completely in the dark before. I believe it covered everything I was asking about except for the fan and fuel pump control.

Also, since we are using the VR input for the tach signal, should I turn the screws on r52 and r56 counter-clockwise 5-6 turns?

That would be a good starting point.