MS3x Nitrous In and JP8 question
 

Reading step 31 here: Megasquirt-3 MS3 DIY board assembly manual

It says that custom firmware is required to use the jumper on JP8.

But here: https://www.miataturbo.net/megasquir...e2/#post815941

Brain says to just jump it and it gives a pullup.

By custom firmware do they just mean custom settings in the tune?

Also what gauge wire should I be using to connect the Pins of my ECU connector to the outputs of the MS3x and MS3.

Instead of starting a new thread I'll just continue this one. Hopefully someone has an answer:

Ok I'm stumped. It worked on the bench but now it won't work installed in my car. Any ideas?

I get 12v at power and ground. And it shows up in my devices. But tuner studio can't connect to it

Update: Testing on the car i get .25 volts where I should be getting 5 on the CPU connector. I get 11.38 On the left leg of U5.

And i get 5V on the right leg of U5 so that part seems to be working too.

Proto area only gets .3 Volts

With the current firmware, JP8 should be left off.

Any ideas about it not working in the car?

Megasquirt Support Forum (MSEXTRA) • board voltage wrong (View topic)

Reading there I have 5 volts at all those places except for D19.

I wish I had a schematic of this board. I'm lost at what everything does.

Doing more digging. Found 5 volts on the top end of F1, and .3 on the bottom end. Does this mean F1 is blown?

Found it. I didn't unplug the tps...that shorted out VREF. I feel stupid.

what are you trying to use Nitrous IN for?

It's only good for trigger something with 12v and not a ground, unlike almost every other input ever.

I was gonna use it for VSS like you talked about in another thread.

Braineack, any idea on this?
So everything was going great:

maybe a bit rich. But then this happened...

Attachment 235224

Smoke everywhere and the wire burnt up. Its too late and it pissed me off so I am going to bed. Any ideas why this happened? The engine continued running while this happened. I have they flyback diodes wired in there.

It seems to be the 12v power wire that burnt up.

EDIT: I dug around and the 12v wire that went to the flyback diode burnt up along with the wire that goes from the fan output (Inj G) to the diode. The wire from the diode to MS3x pin 1 is fine, and so is the power wire in other places.

EDIT 2: Also I didn't jump the fuel pump relay and it still ran, this weirded me out. Any ideas?