I have a 92 4runner 3.0 I.ll be driving down the road and all of the sudden it will start to run rough if i give it more throttle it falls flat on its face. when i pull over to try to clear it i'll hold the throttle at one position the rpms will vari from 3000 to 4500 rpm i let off the throttle and it will not idle after a while it will clear it's self by reving the engine

 

Have you checked for Codes? Tune up done? TP sensor tested? MAS tested? There are 100 things it could be. You will need to do some testing and use results to narrow it down. There is no quick fix for this. Use link in my signature to open the FSM, and run diagnostics.

 

I replaced wires cap rotor plugs and tested them tested fuel pressure checked cataltic convertor no codes coming up black soot coming out of exhaust

 

Follow the diagnostic testing on page 6 and page 8 of the FSM here and report your findings:
http://www.ncttora.com/FSM/1990-1995...e/troubles.pdf

 

Could it be iavc?