car wont idle and has flat spot till 2500 rpm

[gsxroundII]

hey guys im having some trouble with my car idleing and running. when i start it if i dont keep the throttle open then itll just stall and with the throttle open the car is real rough and breaks up until 2500 rpms. heres a list of mod if it helps.
97 GSX
1g 6bolt
big 1g rods, 95 pistons
port an polish head
1mm oversized valves
titanium springs and retainers,
web cams 264 grind
evo3 exhaust manifold
FP green turbo
3 inch exhaust from turbo back
550 injectors 255 fuel pump
Adjustable fuel pressure regulator
SAFC
front mount
any help would be greatly appreciated

Thanks
Phil

 

[leet]

Did this occur after you worked on the car? Or just out of the blue?

 

[jrivard00]

More specifically, did this occur right after the valve job?

 

[leet]

^ Read my mind...