my Supra's early Christmas presents were a new alternator and battery a few months back; plus, i gave her a wash the other day too

unfortunately, my Soop' is naughty every day -- the motor has some sort of hesitation problem; thing is, the car only hesitates when it's warmed up.
what my car does, is that the motor hesitates from idle to about 3000rpm, then from about 4500rpm to redline. the car is driveable in those two rpm ranges, but i can't floor it -- if i do, the motor bogs down and makes a 'machine-gun' noise out of the exhaust. it's really aggravating and annoying; i think i'm just going to start replacing shit to see what happens (spark plugs/wires, distributor/coil, o2 sensor, fuel pump, etc.)
i've taken it to my mechanic several times to see if the problem can be fixed... he's tried several things (new ECU, new AFM, new TPS, new distributor, removed catalytic converter), but the hesitation is still there. when the car was bought (last May), it had this problem. the car had pretty much sat since '96, and in '95 the timing belt was replaced.
i know i should post this up in the Engine forum; but, i've posted twice about this in the General Tech forum, and garnered very few responses.
can anyone relate to these symptoms/problems? meh, i think i'll just save up and buy a 6M from AG :roll:
-Evan