I finally solve the problem about the 3800rpm hesitation.
It was my freaking secondary injectors. I know everyone said to check my injectors. but since they where going pass 3800rpm in a very very light throttle pressure i was thinking that it work. after i reground the feul pump, check the tps, check the pressure sensor, and added more ground.

I found out by switching my primary with my secondary and when i went to start the car after i switched the injector it didnt want to start. I switch it back how it was and it started like nothing ever happen.

just wanted to let people know how i fixs this very painfull problem about the popular 3800rpm hesitation.

gxl/turbo 2 S4 conversion

rebuilt motor with about 300 miles on it
walbro 255 feul pump
greddy fmic
hks ssq bov
3 inch dp and catback exhaust system from racing beat
racing beat fcd
custom intake
all emission off running premix

everything a turbo 2 has i have

soon (mircotech)

 

i still have the hesitation and ive done everything... added 2, 4 gauge wires to the negative terminal, another ground from the harness ground under the intake to chassis, another on the fuel pump, one on upper intake, one on trans. car has brand new fuel pump, secondary injectors, optima battery, fuel filter, spark plugs, newer computer.... and it still happens... and my volt gauge reads about 12.2 volts so i know im getting constant 12 volts to everything...

 

have you check if your pressure sensor work or if the pressure sensor ground is good.