I'm going to explain this to the best of my ability... when my engine is cold it runs like a champ. No hesitation or anything. After a while of driving/warmin the motor up, the motor seems to hesitate frequently when I get on the gas. It will eventually let loose and go... but at first there is ALOT of hesitation. You can feel it holding back... I'll just list the specs of my car, along with mods I did in order to solve the hesiation issue (which obviously didn't work)....
99 Civic EX
96 JDM B18C motor w/ LSD tranny
OBD1 P72 ECU

Replaced:
Fuel pump w/ Walbro 255 pump
Fuel line from filter to rail w/ GSR line.
Brand new altenator and battery... didn't think this would help, but I needed them

And just some more specs in case you are wondering...
I pulled my a/c and power steering(side note)
Replaced spark plugs, rotor and cap.
Also, I replaced the internals of my stock d16y8 distributor with the gsr internals so it would plug righ into my stock harness.
I am running very rich..lot of carbon in the exhaust pipe.

Any ideas?

Thanks!
Matt