hbrew

iTrader: (1)

Is there an up to date picture or diagram that can help me in finding out what wires i need to cut to install mega squirt. I found the picture in the install faq but im kinda confused on what wire on my db37 harness go to where on the ecu harness. and also anyone have a better digram that explains what wire is what on the db37 harness. I think my problem lies in that i bought my db37 harness premade and i dont understand how its wired.



Do i need to cut all of these or just the ones with the star above it?

My harness only has coil 36 wire but i have 2 others i dont know what they are one is f idle and tps vref is one of these my other coil wire?

Also my harness has 4 iac wires do i need these for a 99 install?

My goal here is to just have ms control the engine and have my stock ecu control ignition alternator ect.

Joe Perez

iTrader: (8)

Yup.

You really need to pull the shell off and trace each wire back to a pin.



See above.

If I recall correctly, there are two different colors of wire used here in the stock harness for the four IAC lines, and they're just labeled IAC 1 and IAC 2, without respect for A and B (or vise versa.)

On the circuit board, the four IAC pins don't go anywhere in particular, they just deadend at four pads. So the function of those pins (as with the four SPR pins and the IGN pin) depends entirely upon how your MS is wired internally. In other words, which mods are connected to which pins.

So you need two things, really. First, crack open that pretty harness you bought and map out which wire goes to which pin. Where there are duplicate wires (IAC) put unique labels on them.

And second, you'll need to know how your MS is constructed internally. What pin does the alternator control go to? What pins do the cam & crank input go to? What pins do the spark out drivers go to? All this stuff is entirely up to the person building the MS, and that's what will subsequently drive the decision as to which harness wires go where.

hbrew

iTrader: (1)

what about the coil wires? can you show me what wire on the harness is suppose to be the 31 wire.

Also do i need to worry about the stim thing and if so how do i know if i have it installed already?

Heres some pics of the board

Braineack

iTrader: (62)

'99 OEM Connector Megasquirt DB37

3Y and 3W Injectors 1&3 DB34&35

3Z and 3X Injectors 2&4 DB33&32

3Q VICS DB4 (spr2)

3O IAC DB30

3M IAC12v to 12V

3P Fuel Pump (w/ immobilizer)

3N Fuel Pump (wo/ immobilizer) DB37

3I Clutch switch

3J Rear O2

3G IGN 1, 4 DB36

3H IGN 2, 3 DB31

3E TPS DB22

3F Sensor Gnd to MS GND

3A Gnd DB19,18,&17

3B Gnd DB7,8,& 9

3C Gnd

2K Tacho DB5 (spr3)

2I TPS Vref DB26

2J Crank DB24

2H Cam DB25

2F Knock

2E CLT DB21

2C Front O2 DB23 (not connected to stock harness, will go to wideband)

2B IAT DB20

1V Neutral

1Q Alt Warning light DB6 (spr4)

1O Alt Field DB27

1R Cooling Fan DB3 (spr1)

1I AC Fan

1B 12v DC DB28

EBC DB29 (not connected to stock harness, will go to EBC)

hbrew

iTrader: (1)

what do those translate to this? is 36 and 30 suppose to be the coils?

Ben

iTrader: (33)

This is for a 99? Are you planning to run an NA CAS, or were you going to switch to an MS2 processor? I'd recommend the later.

If you did not realize, the MS1 can not read the NB's funky crank and cam position sensors correctly. MS2 does, and there are a couple of different ways of building the ECU to condition the NB signals.

Here's the pinout of our DB37 harness


As Joe said earlier, there are several pins that dead end at the DB37, and their function is entirely up to how the MegaSquirt is jumpered internally.

hbrew

iTrader: (1)

Im pretty sure i have a ms2 and i found my receipt and i bought it from diyautotune so it should be assembled to their specs.

Ben

iTrader: (33)

The ECU pictured without any doubt has an MS1 processor.

Each assembled ECU that we sell has a sticker on the bottom. What does yours read? What's the order number on your invoice? I'll look it up.

hbrew

iTrader: (1)

the sticker reads

Ms130-c
MegaSquirt-I ECU
w/ PCB3.0

So what do i do about the cam angle sensor? i still have the stock one installed is that not going to work?

Also According to the harness diagram for my ecu harness where do the coil 1 and coil 2 wires hook up to the db37 harness?

Joe Perez

iTrader: (8)

Judging by the pictures, it looks to me like you bought a basic, pre-asembled Megasquirt board in the "unmodified" state.

This board, as it stands now, does not have the necessary circuitry to drive your ignition coils, or accept input from your crank and cam sensors. The Megasquirt, you see, is fairly generic in terms of its basic design. Because there are so many different engines out there, each with different requirements for things like sensor inputs and spark outputs, the MS is built with none of these things on-board. The only engine it's really capable of driving with no modifications whatsoever is one running a distributor.

On the plus side, the modifications required to make it work on a Miata are not terribly complex. On the minus side, I'm not getting a very good vibe so far about your level of experience with electronics and engine managament. Since you already have the wrong CPU for your engine, you might want to consider seeing if DIY will let you send the unit back to them to have the required modifications made.

hbrew

iTrader: (1)

Well this is my first time using megasquirt and im not really having a great time finding the required information to get it to work with my car. So far it hasnt been very easy lol. So i need to see about sending the unit i have back and getting the required mods done. Should i be looking into getting a new db37 harness aswell? or should the one i bought from diyautotune be good?

bigwig

I'm in the process of MS my '99. My research basically left me chosing between these options:

1) DIY PNP - Least Stressful install as DIYAutotune will help you along the way quite a bit.

2) MS2 with Abe FM board (contact Abe for more information) - Slightly more difficult, but Abe will help you along the way.

3) MS2 with added circuits in the proto area/secondary bread board. - Most difficult. Members will help, but if you don't know how to build circuits, this might be too difficult.

I lucked out and found an MS2v3 for dirt cheap. I'm most likely going to buy a board from AbeFM and run the MS2v3 as a standalone. Since I got my MS2 at such a good price, I might try to flip it and take the remaining money and just buy a PNP unit for no other reason than it's 1 case all setup and all I have to do is spend a couple evenings soldering away following some instructions.

I have no issues soldering, but honestly the best and worst thing about MS2 is the fact it can work for just about any vehicle. It makes finding a reasonably priced EMS very easy, but at the same time, getting it all wired and to work for your vehicle can be somewhat of a nuisance. Sometimes it's worth the extra few bucks to just buy a unit specifically tailored for your car. I've taken a couple circuit analysis classes and I never did well in them. I can handle house hold electricity, but anything more complicated, I'm out of my element. Building circuits is not my cup of tea so as a result, I might have to cough up an extra $50 for a unit where I just have to assemble, but in the end, it will save me time and money between trouble shooting and researching.

If I were you, I'd call up DIYAutotune and see what they'd be willing to do to get you up and running.

hbrew

iTrader: (1)

thats my plan so far is to see if the guys at diy will help, so far my car is not running i prolly shoulda read more into megasquirt before i bought it not saying its a bad product but just out of my league on understanding how it works. I want to continue using it but i do need help getting the unit i have setup to work with my car.

Big wig how did you wire up you're ms2 to you car? I still need help and resources on what wire goes where on the MS harness and vice versa to the cars ecu harness

bigwig

I haven't done anything yet. I'm still waiting on my friend to ship his MS2 to me. The benefit of the Abe FM setup or the DIY PNP is it plugs right into the stock harness. I'm sure I'll have to hack into the harness for a couple of wires, but all in all, the whole point of the PNP systems is so you don't have to deal with all the variables, just a handful.

Quite frankly, I've learned over time to limit headaches when you can. From DIYAutotune you can buy an unassembled PNP kit for $425. Brainack on here will assemble and ship one to you for $590. If you can solder, you can also spend $90 on a MS2 board and $100 Abe FM board and get a similar package to the PNP kit. The last option is spend $90 for the daughter board and some unknown amount to a member here to do whatever is necessary to modify your MS2 to run your car.

The first step is to get your MS ready to be wired up. Then you have to worry about wiring it up. At this point, you're not ready to put the MS in your car.

hbrew

iTrader: (1)

So the Ms1 version 3 i currently have is just a paper weight or can it be modded to a ms2?

I'll definitely be signing up for circuitry 101 when i go back to college i hate not being able todo stuff!!! lol

Joe Perez

iTrader: (8)

I don't have time right now for a dissertation, but the only important difference between an MS1 and MS2 is the CPU. The big black chip in U1. Swap an MS2 CPU into that socket, make a couple of wiring mods, build the input / output circuits, and you're good to rock.

hbrew

iTrader: (1)

sounds like a plan thanks again Joe

bigwig

http://www.diyautotune.com/catalog/c...oard-p-86.html

That's all you need to upgrade from MS1 to MS2. Remember, you still need to do some work to get the cam and crank sensors to work still. It requires building a circuit which is stickied in this forum. If you plan on doing a standalone install, you also need to worry about the alternator, air conditioning, and a few other bells and whistles.

hbrew

iTrader: (1)

well i plan on keeping the stock ecu to run the alternator and stuff and just use the MS for engine management to keep it simple for me.

hbrew

iTrader: (1)

Anyone have the schematics for installing the daughter board?