Dead rotor...
 

Was driving home from work today, was accellerating at about 5000 RPM when the engine lost half it's power, there was no smoke, no bang, no grinding or rattling like it ate something. On further inspection when I got home, I figured out the rear rotor isn't doing anything. I've got good spark at all wires.

Oil pressure and water temp are fine. I read somewhere that this engine has a valve that shuts the rear rotor off when the engine is decelerating to save fuel, could this have caused my problem? If so, could someone tell me where this valve is located on the engine so I can check it.

Thanks.

Is this true?

http://www.geocities.com/MotorCity/S.../firstgen.html

According to this site it was first used on the 7 in 81, but a couple people here said it doesn't have one so I don't know for sure.

on the rear intake runner there is a lever use a flashlight and look down the barrel, if its closed then tie it open

btw check for compression on the rear rotor
if the valve gets stuck closed itll kill the rotor, hapend to me once

I'll check that too before I tear it apart, thanks.

is that the studder valve?

Shutter Valve. Coasting Valve...whatever.

http://www.mazdatrix.com/faq/shutter.htm