Sounds like your computer is screwed to me. That's just based on an example of the exact same thing that happened on an old 88LX 4 banger I had. Same exact thing. A mechanic I know wacked it with a screwdriver. Damn thing ran perfect. I felt like an idiot. Oh well, that cleared up a problem that I had for months. Incidentally the engine blew up the next day. Tell me that's not ironic?
Anyway, sounds like it's the computer, or another emissions sensor. Otherwise the problem wouldn't go away when the car was shut off and refired rolling down the road.
Still, you said you cleared the computer, let the engine cool off, started it and it lost a bunch of power?
Here are my best guesses.
- Computer
- MAF Sensor
- TFI Module
- Fuel Pump
Those are just some ideas that I have.
I hate those kinds of problems.
Good Luck!