MS2e Rev '91: What drives INJ3/INJ4 for sequential injection?
 

I have a MS2e and all the research I have done shows it supports sequential injection. It doesn't look like the DB-37 has pins for INJ3 and INJ4 and looking at the pinout for the MicroSquirt-module V2.2M it is not super clear what pins would be driving those. My best guess would be pins PT6 and PT7 on the smaller 10 pin J1 connector. Is that true? If so, are those brought out to the stock ECU connector because it sure doesn't seem they are on the DB-37. I understand that the stock injector wire harness will need to be modified.
ELI5 What pins will I need to use to get sequential injection working on a '91 1.6, thanks.

I'm not too clear on what megasquirt you actually have. Not all of them have 4 injector drivers on the board. For those with only two injector drivers on the board, you need to add two new drivers. I just upgraded my DIYPNP to support sequential injection, and this is the kit I used:

https://www.diyautotune.com/product/...injection-kit/

PM @Reverant.

The PDF lists it as the Enhanced MS2 V5.4 - Firmware 330f

I figured I would ask here before bothering him with a PM if anyone else had already had it working with this version of MS.

you can look on the proto area of the board if this is a diypnp that rev built for you. he might have just done it there. look for the green board with the 2 black 10mm squares. thats the sequential board diy sells. It will either have that or it will have those black squares(drivers for injectors) mounted in that proto area.

https://www.miataturbo.net/attachmen...ine=1466780871
https://www.miataturbo.net/attachmen...n-dsc_1425.jpg

in a MS2E the drivers will be built into his own enhancement board.

https://www.miataturbo.net/attachmen...ine=1466784753

How about those two by the J2 head? Does Rev give out the schematics to these boards? I PM'd him but haven't heard back. I know he is a busy man.

No he doesn't. Send him an email; info@mslabs.gr and make sure you put the unit serial number in the subject line. He's also on FB if you look.

double post...

those are probably it. you can trace them back to where they go to, middle pin (or the rear tab). They should connect to PT6 and PT7 on the left most pin (looking at pic). Right pin goes to ground.

Thanks, I'll reach out there.

Ok, I figured they had to connect to PT6/PT7, I just can't figure out what pins on the main harness connector they go to. Now that I have some verification I can try and trace them to the correct pin. Thanks.

I had the same question for reverant a while ago: https://www.miataturbo.net/ms-labs-m...jection-81345/

Short answer: the wires for INJ3/4 are run to the main ecu plugs. It's designed to be a drop in replacement for later models with sequential injection already present in the harness.

All you need to do is add 2 pins to your wiring harness and feed them under the hood.

I ended up ordering some extra crimp on pins and using new wires, I decided that was easier than re-purposing old wires, but I'm having a hard time figuring out where I ordered them from. If you do some searching you'll find the Tyco part numbers online. Sorry I can't be of more help. I'll check the packaging when I get home, I know exactly where the bag of extra pins is.

Remove jumpers JP4 and JP5.
Install jumpers on JP7, JP8, JP9, JP10.

Change the settings to use additional drivers (from standard drivers) and sequential injection.

4U = Cyl 1
4V = Cyl 2
4Y = Cyl 3
4Z = Cyl 4

Thank you, one final question. Where are 4U,4V,4Y, and 4Z. Looking at a stock ecu pinout there is only connector 1 and connector 2 with associated letters. And akbloom's post is using:
Pin 2U -> Cyl 1
Pin 2V -> Cyl 2
Pin 2Y -> Cyl 3
Pin 2Z -> Cyl 4

He is apparently also using a MS2e and a 1.6L. Why are they different?

connector 4 is connector 2.

N76 covers 4 different connectors. fits 90-2000 miatas

Stock 1.6 only has 2 but the other years have more. see pic below. easier on diyautotune side to just number them like the other 4 connector setups do.

https://www.miataturbo.net/attachmen...ine=1467056764