using 2002 ECU on 1990 Miata
 

I know that modifying an NA engine harness and using MS is the easiest way to run a VVT motor in an NA, but has anyone swapped an entire NB harness into an NA chassis?
I am trying to avoid having to spend $1200 and having an almost complete 2002 wiring harness it is temping to attempt to swap the entire harness into the NA. I know ill probably be doing a lot of splicing but it may be worth the $1200

you realize that swapping and splicing all the required crap will take you weeks and you'll want to kill yourself from frustration right?
and in the end you'll be left with a hunk of junk. (I say this because 9 out of 10 "spliced" harnesses I've dealt with had all sorts of funky electrical issues after, making tuning and overall control a giant nightmare)
You'll be begging to spend "ONLY" 1200 to "fix" the problem in the end.

my rule of thumb: cut/splice the least amount wiring possible on any car ever. but then I'm not a wiring pro.

Theoretically it is doable, not sure if it is worth the amount of work and effort to get it to work. The 1.6 wiring harness is one harness for the ECU and the rest of the car. So it would be extremely hard to remove it, then wire in the 2002 harness. It may be easier to build a boomslang to go from the stock 90 harness connector to the 2002 harness connector. Then just wire in the plugs in the engine bay back into the stock harness.

Yeah definitely easier to splice in the NB plugs to the NA loom. That's what I ended up doing on mine even though I had the wiring loom for the NB. You could remove the female plug from the NA ECU and wire that to the male plug of the NB ECU to let you hook up the NB ECU (assuming you have the NB wiring loom) or just use an aftermarket ECU.

Honestly... especially since we have all winter, you could faaaaiiirrrlllllyyyyyy easily (I say fairly, because it's still going to be a LOT of work) rip out the entire 1.6 harness including body harness, set the VVT motor in the car, run the engine harness and stock ECU in there, then fill in the blanks on the body side of things with a Painless kit or similar. Would still require some trickery in places that i can think of (gauge cluster comes to mind), but it's doable.

Whether or not the large amount of time it would take would end up being a "net profit" over just getting the Megasquirt you would need to retain 1.6 stuff would be up to you. I'd say by the time you get the body harness kit, various other supplies/tools, and the amount of beer you'd have to feed me, you'd probably be $500 deep, and that's assuming you're starting with a 100% complete engine harness/ecu and stuff.

I'm definitely down to give you a hand with this, though.

Have you ever driven a stock 01+ car? Do you know how bad that stock ECU is? I cannot fathom why you would willingly pick it over a $1050 MS3 Basic which installs 100x more easily and gives significantly more power across the entire RPM range. You're already spending the money on the VVT motor, so presumably it's a performance-oriented build, and the ECU is some of the cheapest (in dollars per horsepower) power you can buy for the car.

Building your own megasquirt would be easier than swapping harnesses.

Is the stock ECU why every NB2 i've driven feels "dead?" I understand that it's superior to the earlier BPs, but i've never driven a more "boring" motor in a sports car in my life.

^^^ seriously if you're willing to rewire the entire car then you should be willing to take the ~2 hours it takes to solder the ms3x kit together.
Its $500.... All told with every sensor/connector/wideband/etc it was ~$800 to get the ms3x in my car.

:facepalm:

You know, because other BPs are so exciting. :giggle:

Ok, Ill just buy a MS3 basic then. I don't think I need a pro and $1050 could be done. I rather work extra for a few days in the hospital than freeze my ass off in the garage this winter rewiring my car. You guys convinced me.

Good, good. Now freeze your ass off in MY garage this winter rewiring my MX6.