Wiring Question - Injectors
 

Okay, I've looked, re-looked, and looked yet again on my harness.

As far as I can figure out, for injectors, it is wired 1+3 and 2+4, I would assume that it would be wire 1+4 and 2+3.

Someone correct me if I'm wrong, please, on the signal wires.

I had to move over to m.net to search, this makes me sad in the pants.

http://forum.miata.net/vb/showthread.php?t=238496

There's no problem with 1+4 and 2+3 according to this, what else do I have to do to my MS2 to make it okay with 1+4 and 2+3?

That is correct. It's weird, but correct.


Yes, you waited a whole seven minutes for an answer before giving up.

http://forum.miata.net/vb/showthread.php?t=238496

Nothing. Just tell it you have two injector channels.

Thanks Joe, still feeling really weird about 1+3 and 2+4.

Naw, it had me WTFing that m.net had the information, and mt.net did not. Seriously, how? Searching m.net for MS-related questions is like asking Faeflora to do bodywork on my car.

Roger. So all injectors inject fuel on all injectors at every injection event? Or...? I'm not really getting how you can swap from 1+3 and 2+4 to 1+4 and 2+3 without ------- something up, unless all injectors inject fuel at every injection event. Equally, if this is the case, I don't understand why you don't just run one wire for injector signals, instead of 2.

That's ok. At first, I felt weird when Hustler invited me to share "secret playtime" with he and his uncle. But you get used to it.

It's not just the Miata. Most (all?) 80s vintage I4 engines with banked port injection are wired this way.



Yeah, it's a shame nobody at MiataTurbo thought to put this information at the very top of the Megasquirt-specific folder, in the sticky thread entitled "SUPER Important Megasquirt Threads" under the very first link at the top called "How To Make and Install Your Own DIY Megasquirt" wherein you'd find that information conveyed in the picture near the middle of post #3 under the heading "90-93 1.6L STANDALONE HARNESS WIRING."


I just don't know what we were thinking...


Props for most creative insult I've read all day. :bigtu:


No.


Ideally, you'd set it up like everyone else's, by specifying "Alternating" under "Injector Staging," such that each injector bank fires twice per engine cycle, alternating A-B-A-B.

But that's just how I'd do it if it were my own car or any of the others that I've worked on in recent years. You're free to be creative.


Injector timing just isn't all that critical. It's best if you have four injector channels and time the injectors such that each individual injector pulse ends right about the time that the corresponding intake valve opens, but it's just not that big a deal if the timing isn't perfect.

Remember carburetors? Remember TBI? Remember CIS? None of these schemes timed the fuel delivery to valve events, and they worked fine. Slightly higher idle emissions then a modern engine, but like Pusha's mom at closing time, they were good enough.

Thanks for the explanation, Joe. I kind of sort of vaguely "get it" now, I'll just have to figure out how to bend TunerStudio to my will on the injection settings!

It's nice that Mazda flipped the pairing on the injectors - it makes it much easier to troubleshoot when something goes wrong.

Injector timing is for those of you who are gas mileage weenies - play with it until you have the richest AFRs for a given injector pulsewidth, then re-tune the fuel table.

Why aren't you doing sequential fuel?

No MS3 - I'm running a MS2, so I'm wiring so I can swap over to seqfuel with a minor change, but that's part of trying to wrap my head around what Mazda was doing with the injectors.

So, you're aware that JBPerf has a mod that allows you to run full sequential on the MS2, right?

http://jbperf.com/sequential/index.html

I am aware, Joe, but I'd rather pick up a MS3 then deal with modifying my board for Seqfuel.

----, if I have to get seqfuel on the MS2, I'm gonna sweettalk Brainy into doing the mod for me.

Related to the above:

Install harness, gauge cluster goes nuts. Even turning the car off doesn't get it to stop it's bonkers on/off/on/off clicking - I have to disconnect the battery.

Unplug everything, gauge cluster is fine.

My hunch: It is the water temp sensor I miswired. Is the stock Mazda temp sensor possible to wire incorrectly?

Alternatively, did I somehow ---- up wiring my temperature sensor and/or CLT sensor and put voltage on a ground? I thought I matched colors exactly.

Final alternative: Miswired the injector plugs, but there's nothing there to miswire. Seriously, there's nothing there to focking miswire - shared 12v to all points, then point to point injector triggers.

What the fuckity ----?

I tear the harness apart completely, look everywhere for a problem, double and triple check wiring, repeatedly check continuity, etc. etc. find no problem.

Go back out, plug it in, it works. What the ----?

I mean, it idles rough as ---- still, but it works no problem (Not running it at length at this time of night). What the ----?