1990 Miata 1.6 MS2 Not starting
 

Hello everybody, I'm new to the forms and was wondering why I can't get my dang Miata running. I have the fuel pump connected but whenever I crank it over i get no rps and no spark.. however when I put the old ECU in it starts right up and run like a top. note being said with the wiring I do not have a D14 or any spark wires except for the green/white and brown one shown on "my wiring 1" I bought the board from DIYAUTOTUNE as well as a 24" MSPIGGY from them. thank you for your time.

side note. i bought it assembled as a w/PCB3

What board version do you have, and how is it configured for spark output?

I'm have same problem with car not starting. Running pre build ms3x expansion v3.57 wired in to diybob board.

I would strongly recommend you start a new thread. There is a big difference between having the same symptom and having the same problem, and keeping your discussion separate will help avoid well-meaning advice that is only good for the person who started this thread. Or, since this is MiataTurbo, malicious advice that is only good for the person who started this thread.

I think I can help figure this out with you if you haven't figured it out yet. I have the same year as your car as well as the same board, and the same piggy; only difference is that it was assembled by me. That being said, I know what's wired inside my board. If you're not sure how yours is wired then you're going to have to open your board up to find out. I assume it's probably wired like this from MiataWiki. If it's not then we can work around that but you're going to need to know how to wire your IAC's for ignition. Follow the write up on that linked page and if your car still isn't starting, which is what happened to me, then re-try how your ground wires are wired. What I did was: out of the 5 plain black ground that go into the MS, I wired 3 of those plain black ones to 2A and 2 of those plain black wires to 2B. Then there are also 2C and 2D which come from the same wire. We'll call that 2CD. I wired 2CD into the black and white signal grounds because 2CD is the ground for your sensor wires in the stock setup. As you probably figured, you're going to need more that a few sensor wires hooked up to that sensor ground so I added 5 more wires attached to that black and white single ground. One last thing to try is to take the black ground wire from your CAS and send it to the black ground wire on the shielded wire.
After you have tried these things post in this thread again and I'll try to help some more.
Another thing that is coming to mind as I close up my thoughts is to go into Output Test Mode for ink/spark see if your spark plugs are firing. You'll have to take them out of each cylinder to see if all of them are firing correctly. just set them on your intake manifold or anything else that is grounded while you're testing.
Best of luck to you!