I may be wrong here but shouldn't the crank input be setup like this



I mean this has worked for me with ms1 and ms2

 

I'm using the unused bolt near the ECU.

 

Grounds are important. Run "good engine ground" pins to the following locations as pictured In this thread: https://www.miataturbo.net/build-thr...6/#post1017483

I believe ran three to the front and three to the rear. These are NOT sensor grounds btw...

 

Wow, thanks Chi, very detailed build thread. Man, I hope my stuff doesn't get that hairy! I am striving towards simplicity and reliability. Will certainly install grounds to the engine block for sure.!!

On another note, showing some progress with the MS. Well, I at least saw spark earlier today. Let's just say I had a "orientation problem" when I started the harness build, so stuff was not going where it was supposed to go... lol. So who knows what damage was done to the MS as all these signals were crossed. Felt like a idiot, needless to say!

I did a bunch of *stuff* to it and ended up frying R20. After replacing it, I would then run TunerStudio and when I increased RPM, the MS would go offline. I could see that I2 on the stim was not firing. Figuring that R20 was fried, pulled out the DMM looking for other components that may have been fried as well. Then I came across Q15 which was installed *** backwards!!!

After fighting with removing the solder from the through holes, (heating up and using a can of air to blow that **** out works wonders..., my desoldering wick didn't do squat) and popping Q15 back in I2 was good.

After that, I popped the MS back into place, reloaded f/w, basemaps, etc. First thing I expected to see was the tach work, but it didn't. I then pulled out the DMM to check for voltage at the CAS sensor inputs. After I did that for some reason the tach started working! Maybe this is a sign of the grounding issue? or reset issue I have heard about?

The car seemed to want to start with a fire or two here and there... but that's about it.

So definitely making some progress...

 

Not sure if you are talking about an orientation issue with the DB37, but I will say that my life became much more simple when I switched to a crimp style plug. That way if I goofed all I had to do was push the pins out.

 

Interesting... Dont think I have seen this mentioned elsewhere to follow. If you didn't use it, I assume you'd be sparkless? What year was your car btw?

 

94 with a 94 wiring harness controlling a 99 engine
But for all intensive purposes its a 94 (94 CAS and was running on 94 coils prior to COP setup)

 

I think this is key. Will give it shot tonight.

I'm not getting spark and the spark I was getting the other night I believe was some sort of fluke.

From what I measure I don't get any voltage change as I turn the motor over on pin 24, but do get voltage change on pin 25.

I have also ordered a jimstim which should be on the recommended instructions in order to simulate the Miata's ignition system.

 

Yeah give that a shot and hopefully everything will work out for ya

 

That 4G63 circuit mod didn't change much. Waiting for my Jimstim which hopefully will be the end all/tell all !

 

Ran a single 10GA wire from the db37 right to the same ground point as on the front of the engine block. My subsitute for running multiple ground wires per the directions.

 

Check out this thread:
https://www.miataturbo.net/mspnp-55/...7/#post1094563


start on post #18...

I don't know if it is going to be any help, but I know in my build the more I read the better I was able to figure out stuff.

 

So, removed these changes since they didn't seem to work. Resoldered a wire that was dangling because of removal of these components. Guess what spark!!!! and progress for a change!

The car is now running however very lopy. Needless to say I must have had a crappy solder joint! Time to connect the rest of the sensors..!!! (MAP, IAT)

 

Glad to hear you got it running! Yeah they don't tend to idle well without sensor inputs such as MAP!

 

Good job. Now add the stuff you need to make it run and get it on the road.

 

Assembled the JimStim 1.5 yesterday, and wow, that thing is really nice!

Provides out of the box Miata signal and lots of flexibility in terms of seeing what signal is on what pin!

Anyway, already have spark sorted out, but nice to know software/hardware is working as expected with the proper signal sent to the MS.