Injector outputs in standalone harness
 

After debating it for about two years I finally started building a Megasquirt for my 91 1.6 a couple of weeks ago.

I'm building MS1 v3 standalone. I have the 64 pin connector.

Everything is nearly done, but I'm a little unsure about the two injector channels on the harness.

In this post https://www.miataturbo.net/forum/t29685/ the diagram provided by miatamoxie shows pins 32/33 (blue) going to 2V at the ECU for injector channel 2 and pins 34/35 (green) going to 2U for injector channel 1.

However, in this post by Joe it shows them the other way around; 32/33->2U and 34/35->2V.

Based on the diagram at http://www.miata.net/garage/ECU_Pin-Out.png 2V=channel 2 and 2U=channel 1, but my question is which pins on the DB37 relate to which?

Thanks!
Andy

I can tell you with 100% confidence that 2U - 34/35 & 2V - 32/33 works. But, IIRC, it also doesn't really matter which is which.

Excellent - thanks. I'll leave them as they are and stop worrying about them then :)

One interesting thing to bear in mind is that, if you build and tune your MS to DIY's original build spec (particularly the CAS setup in the software) then both the injector and ignition channels wind up being backwards relative to the factory callouts.

For the spark, this matters, and is immediately obvious.

For the fuel, it's more or less a wash. When I first built my MS, I was still running a stock CAS. Using an oscilloscope, I observed the firing order of the injectors on the stock ECU, and then wired my MS to match this order.

Sidebar: I'd completely forgotten that I made that document!

lol - well I'm glad you did make it, it's been very helpful!

Here's what I've done so far:

• Base build following Megamanual
• CAS mods from DIYAutotune instructions
• PWM idle valve mod
• Fans mod
• Doing your "better spark out" mod tomorrow when my transistors arrive
• Loaded latest MSnSE firmware
• Loaded base MSPNP map from DIYAutotune
• Not connected anything to car yet, but everything was working in Megatune (not tried it since CAS mod though)

I was determined to get to the end of the build without asking any questions but I guess I may ask when I come to the software bit based on what you just posted...