What type of problems will stem from a dirty rotor and cap?

I'm having problems with acceleration after 4000 rpm...
ussually that in the middle of my powerband.

I was told it might be the rotor and cap... in the past month I replaced-->

valvecover gasket/hardware ...OEM
timingbelt w ...........................OEM
spark plugs w .........................bosch platinum4
plug wires ..............................MSD
fuel filter ................................AEM
oil filter...................................change with royal purp
cleaned throttle body dust/carbon and lubed throttle cables
battery ................................optima yellow RT

I've checked fuel pressure.. it seems to be right where it need to be like 30-35@ idle :: and 40-45while revving.

Is there some sensors that could be effecting my acceleration from idle to 4k and then 4k and up??