thirdgen

iTrader: (26)

So I bought an MS 1 with a 3.0 that was off of a running a 97 miata, but I have some wiring issues. The car it came off of was using a parallel setup, which is the way I will be using it. I had a boomslang harness made for my 99 and the wires are as follows...
1) 12V
2) IAT
3) Knock
4) Gnd
5) Coil 2
6) Injs 2&4
7) CLT
8) Gnd
9) TPS
10) Coil 1
11) Injs 1&3

I read the wiring diagram for the DB 37, and am confused a bit as to what goes where. I have DB37 pin 20 to my IAT, pin 21 to my CLT, Pins 32 & 34 to my injs, but as far as my grounds and my coils...what pins to I wire these to? I am going to install a NA CAS, what pins do those wires go to? The NA CAS has 4 wires coming from it...if I'm not mistaken, 2 should go to MS, 1 is a 12V, and the other is a Gnd. Where can I get this sensor, preferably with a pigtail?

thirdgen

iTrader: (26)

Forgot...Brown analog wire from my LC-1 is on DB37 pin 23, correct?

patsmx5

iTrader: (16)

paul

iTrader: (21)

that's an awesome image.

thirdgen

iTrader: (26)

That is an awesome image...so on my boomslang, there are 2 injector wires. 1 for 1&3 and 1 for 2&4. I spliced them with DB37 pins 32 and 34. So the 12v from 1B on my factory harness goes to DB37 pin 28? What pin or pins on DB37 do I splice my coil wires to?

patsmx5

iTrader: (16)

See on the second image where it says "COILS"? One says "COILS 31" and the other "COILS 36" the number is the number to hook to on the DB 37. So coils go to DB 31 and DB36.

Joe Perez

iTrader: (8)

You should split the big heavy wires you're using for your injector lines and bridge them across two pins each, such that 32/33 are bridged, and 34/35 are bridged. Or just use four wires, one per injector per pin.

Grounds... Pin 2 and pins 7 through 19 are all grounds. Pick five or six of 'em and run heavy ground wires to them. Connect a couple of them to your boomslang grounds (3A, 3B, 3C) and run the others direct to the head. You don't have to connect every single ground pin, but you can never be too well grounded.

Coils... This actually changes depending on how whoever built your MS wired the spark output drivers. The "officially sanctioned" method is for SparkA to hit pin 36, and SparkB to hit pin 31. If you use an NA CAS, and set up your wheel config as DIY suggests, your spark outputs will be "backwards" (relative to common logic) so SparkA will drive coils 2&3, and SparkB will drive 1&4.

Yup.

Like SparkOut, CAS in pinout varies with whoever built it. The usual standard is CKP at pin 24(Techin), and CMP at pin25 (IAC1A).

Wire color at the CAS pigtail:
W/R = +12
B/LG = GND
W = CKP
Y/L = CMP

From an NA. Or from the large pile of them that is no doubt building up at the entrance to the seventh level of hell.

Yup.

thirdgen

iTrader: (26)

So I finished splicing my DB37 to my boomslang except for 1 wire, the knock sensor wire. Does that go anywhere from my Boomslang to the DB37? I have 6 wires left on my DB37...pin 24 and pin 25 which are for my CAS, pin 23 which is for my LC-1's brown analog wire, pin 27, pin 29, and pin 37. Where do those last 3 go?

patsmx5

iTrader: (16)

If you are keeping the stock ECU don't hook up DB 27, 29, or 37. 27 and 29 are for idle control, and 37 is for fuel pump relay. Note all I'm doing is looking at the wiring diagrams I posted to answer all your questions.

thirdgen

iTrader: (26)

So aside from the CAS...that looks like it. Thanks for your help guys.

Joe Perez

iTrader: (8)

The MS is capable of knock detection, however it requires both an internal mod and an external filter/amplifier such as KnockSenseMS. So if you do not have both of these things, then the knock sensor is not connected to the MS.

To clarify 27 and 29, like 25 and 31, are general-purpose pins. Although they are labeled IAC, they are actually not connected to anything internally and are usually used for mods. An example of this is the fact that you have the CMP input mod connected to IAC1A, at pin 25.

37, as Pats' said, is a dedicated FP wire which you will not use.

kenzo42

iTrader: (6)

What triggers the fuel pump if you don't have pin 37 connected and NO AFM present? 91 parallel DIY install, btw.

Or does the above quoted text only apply to PNP?

Matt Cramer

Absolutely nothing - you must have one or the other connected.

The PNP has a different fuel pump control circuit. Pin 37 is internally connected to a circuit that takes over part of the starting circuit to drive the fuel pump relay.

Braineack

iTrader: (62)

unless you jump FP and GND in the diagnostics box like us lazy folk.