I have a Ford Probe 2

I have a ford probe 2.5 v6 24v 1995. 140000 mileage
problem of sudden acceleration. I ask for help.
During rapid acceleration, the engine sound change, poor speeds, it seems like it runs on three cylinders.
during the gradual acceleration of the car is going well and the sound is good.
So the problem is in hard acceleration, the engine is choking, change the sound, and loses power car does not report any error, what's the problem.
Just to draw your attention, when I reduced the gap on the spark plug with 1.1 mm to 0.70 mm in the car behaves nicely with hard acceleration, but stops at the gas constant, and badly at idle.
I replaced the fuel pump, new ignition cables, new spark plugs, cleaned the injectors. The car only accepts spark plugs with 2 or 4 electrodes.
Now in it FR78X Bosch Super 4 with factory 1mm gap, but that is not enough so I had to cut the gap to 0.8 mm and the car suddenly accelerated normally
receives, but breaks the constant moving and restless working in neutral.. When I put the candles with one electrode situation is further exacerbated by the engine when sudden acceleration has totally choked sound as if working on 3 cylinders.
Please if you know what's the problem, please help me