Rough Idle, White smoke
 

A coworker has a 93 twin turbo that's been sitting in her garage for several years.
She bought it new. It has 69k miles. One day when driving home it started running crappy. By the time she got home there was fire coming out of the exhaust. I looked at it today, she want's $6000 for it. The car looks perfect. It starts ok but it runs rough. It smokes a bit and it smells like unburnt fuel. Someone told me it could be a timing problem. Do Wankels have timing belts? This is my first post and I know nothing about RX-7's. I do know 6 grand is a good deal, but I'm trying to determine whether a major engine rebuild is going to be required.
Can any of you Rotary engine experts give some ideas what might be wrong with this car?

just got mine and same sceneario, i'm going to try new plugs/wires first

pull the radiator cap and rev it from under the hood. white smoke sounds kinda like a blown coolant seal. if water shoots out of the coolant cap or you see a lot of bubbles, it's a bad sign

Does a blown coolant seal require the engine to be pulled out of the car?

check to see if the map sensor is on

yup, blown coolant seal requires not only for the engine to be pulled, but for it to be taken apart

I still want it. It will be a....uh.....learning experience..

I tested the wires on the map sensor. I don't have a vacuum tool so I couldn't do that part of the test. The map sensor reads 2.2 volts at idle. I think I read it should be 1.3 volts at idle and 2.4 at 0 vacuum.
From the readings I'm getting, does it sound like the map sensor is bad? Or do I have a vacuum leak?
How much does a map sensor cost and where can I get one?

Mine cleaned up with new plugs and a spirited run after I got it back on teh road, try it out!

The white smoke has cleared somewhat. Now I get brown smoke at high rpm, although I did put quite a bit of injector cleaner and octane boost in the gas tank.
The idle problem goes like this. After I rev it up and the engine gets warm. The idle starts to die and the air pump kicks on. The engine definately seems to run smoother with the air pump on. Do you think it's just running too rich because of the gas additives? I'm guessing other possible problems would be the O2 sensor or maybe the main catalytic converter?