I'm in the midst of quite a few transitions on my car; taking it back to a more-or-less stock form, from a turbo kit that I personally didn't install. As such, I'm missing a lot of parts, and I'm discovering them one at a time.

I just discovered what is hopefully the last missing part (thanks to a friend with a mostly unmollested RX-8 that she let me poke and prod at in order to figure out what mine's missing), but I don't know what it is, nor what it does. It is a little silver box - looks like a tiny computer box of some sort. It's roughly 2"x2"x1", and it's bolted to the chassis, right underneath the air pump. What is this part, and what does it do?

 

CIA tracking device?

 

Fuel Pump Resistor
Mazda's p/n N3H118831

 

^ What he said.

 

Thanks guys. I've got it ordered. Hope this fixes my problem...

If I didn't have this installed, would it possibly be the cause of rough, bouncing (200rpm-2,000rpm intermittently) idle, and stalling whenever I hit the gas?

 

Just a heads up to you two who helped me; I got this part it, threw it on the car, and she runs beautifully now. Thanks for the help in identifying my last mystery piece!