Electronic Boost control from unused wire in loom
 

I just got my EBC in the other day from DIYautotune. I want to wire it in but what I see most people do is connect P6T to boost control in and boost control out to one of the DB15 pins. I want to avoid using P6T if I can so I can run sequential injection later on.

I really don't want to run a wire into the DB connection in front of the MS so I was wondering if anyone has used something from the stock wiring harness to run boost control. That way the install looks nice and clean. I have a 90 1.6L car without AC or PS, has anyone tried to wire their EBC in like this?

Yes you can run it through any unused wire in the engine bay that goes back to the ecu. You would just need to hook up the corresponding wire at the ecu to whatever output you set EBC to. I don't know 1.6 cars off the top of my head so I can't really recommend what wire to use. Maybe something in AFM connector.

Evap purge solenoid has 12v and a switched ground wire at the ECU.

That would be great if I can use one of the AFM wires for this. It's close enough that I could easily hide the wires and mount the EBC in a coolish location. If I was more confident in my ability to read a schematic I would do the leg work on finding an unused wire but, my electrical ability falls short of my mechanical...by a good margin. :facepalm:

Do you know which wires those would be at the MS connection by chance? That would be good to use since I don't have it in the car anymore.

So I think I found it. It's a yellow wire labeled 2x on this diagram.
https://www.miataturbo.net/attachmen...ine=1455310216

So in the Megasquirt itself how do I identify where this wire is pinned?

Here is the .PDF in case you can't see the hosted jpeg. http://www.miata.net/garage/ECU%20Pi...90-93%20MT.pdf

What MS do you have?

DIYPNP

So factory ECU connectors right?

Right

It's wired as 4X on the jumper board inside the DIYPNP for a 1.6 miata.

So will the wiring look something like this...

Inside Megasquirt
4X to Boost Control Out
IAC/PT6/PA0 to Boost Control In

Inside Car
Polarity isn't important with the MAC valve so..
Yellow wire from purge valve to one wire on the MAC valve
Other wire on MAC valve to any ground


Is this correct or is my understanding wrong?

No, the megasquirt is a switching ground in this application. The other side of the valve must be wired to 12V. That's why the purge valve is cool, it is an ECU switched ground wire and a 12V wire off the main red/white engine feed.

Or you could wire it to ground, just won't do much at all.

Oh, interesting.

So both the wires going into the purge valve can be used here by just hooking them right up to the EBC (red/white and yellow wires)? I am assuming that the wiring inside MS was correct in my post though?

Yep, that's it.

You're my hero. :likecat:

I always wire it through the AFM/MAF connector on my MS setups since 9:10 people put the EBC solenoid near the wastegate.

power can be tapped at the diagnostics box or the blue power connector.

Not that I've ever heard of anyone having a problem before, but the DIYauto valve is only rated at 122f/50c.

Since you should always source the wastegate source after the intercooler, as close to the throttle body as possible it just made sense for me to mount it off over there, near the throttle body on the cold side.

I also put it in the AFM connector.

With ebc the location of the wastegate source doesn't matter.

What connection in MS do you make for the AFM to run it? I forgot about the blue power plug. I could just put a spade connector on it and wouldn't have to chop into my harness that way. I only use the blue connector to check timing anyway and the EBC can be open for that.

I used the maf wire i believe