ah ok thx, its making sense now! think mazda would carry the factory plug for this, could splice or solder it. or does anyone else have a better/easier idea?

Leave it off? :-)

does anyone know if you can use the Nb IAC/throttle body with the NA1.8 engine management?

I don't mean to hijack this thread but I was originally planning on doing this same swap before my head was jacked up by the shipping company. I now have the option for doing a complete 99 engine swap which would be more expensive but would give me some leeway in timing and flexibility for my build. Other than swapping in the CAS from the 97 are there other issues that I have overlooked? I already have my MSPNP for managing it and I do know about the variable intake runners. Aren't the cast iron blocks the same?

compression is higher on a 99, 9.5:1 vs 9.1:1, ive heard things about connecting rods being stronger on a NA 1.8 but who knows?

I am aware of this. I am going to be rebuilding the engine with forged pistons and rods with 8.5 compression ratio. 9.5 pistons are just an extra part left over.

haha, yeah thats easiest but im in a need of low-end tq, especially with my wide open exhaust >.<. after ive put some miles on this head ive noticed more topend hp for sure tho. or i could just wait til MSPnP and a BEGi kit and that would take care of tq problems hah.

Bumping this thread from the dead for the sake of this question. Reason being is that with the '95 TB on my '99 IM, the harness for the IAC is jammed into the silicone inlet tube (FM intercooler kit), which in my mind, is not an optimal situation. I don't have much of a choice for movement either, if I move it to get it only slightly off the harness, it kinks the hose for the reroute. The '99 TB is a much better solution if it will work.

I thought I had read that the voltage for the TPS is different, but if that's the case, the sensor could easily be swapped between TBs, but will the IAC still work properly?

What are you running? a stock NA computer? Get a real computer, like an MS, it'll run everything just fine. The downside is the extra 50 horsepower, but you can just leave your parking brake one to compensate.

Absolutely. I'm running a stock NA computer on my GT2871R powered car. lol No, I'm running a Link. (New EMS will come someday down the road.) I quoted hustler because I'm trying to figure out if the IAC will still function properly if I swapped the NB throttle body on.

I don't KNOW, but I would really think that the two must both run off 12 volts. Getting something other than 12 is hard. It COULD be 5, but that would be hard. They could have wildly different characteristics... so I guess you're right to ask, but I would think a retune of the idle would be all you'd need. It is a guess, though.