feels like fuel cut out at 4000 - 4300

ok about two weeks ago i noticed that when i take my car up to about 4000rpms at half throttle the car cuts out and then if i floor it at those rpms it like hesitates. I have replaced the distributor cap and rotor, spark plugs, fuel filter,and i checked my fuel pump is working fine i made sure my cam shafts were at tdc when the no. 1 cylinder is at tdc and that was fine. Any ideas would be helpful. Oh yeah if it helps i have aftermarket camshafts,cam gears, under drive pulleys , full exhaust system, cold air intake, and ajustable fuel regulator and i have a fuel gauge that is reading at 40psi at idle and at full throttle it goes up to about 46psi and my air/fuel ratio gauge is showing that im running lean. Any ideas?

i forgot to metion that i checked the mainfuel relay and that is fine also.

O2 sensor??

i replaced that too

try throwin some fuel injestor cleaner my car did that beacause of some water in the intake i opened my hood in the rain and it got in the resonator

Did you try your ignitior sits right beside the coil in the distributor… When i had all of ignition problems , i got the specs for the ignitor and coil and found out the ignitor wasn’t reading within specs…

just my .02 cents

its not fuel injector cleaner cause i have ran two bottles of that through it and it didnt help and when i pulled of the plugs they were all evenly worn which meant they were all getting and burning the fuel equally. but the igniter i have not checked or the ignition coil however my car is running lean according to my air/fuel ratio gauge. does this sound right cause to me it still doesnt sound like that would be the problem but i will check it out tomorrow. thanks , nemore suggestions would be appreciated.

Maybe fuel filter?

have you replaced your plug wires also?

i had sort of the same prob in my hayenes manuel it said there was an air intake leak so i just started pullin off vac lines and put grease on them to help them seal that was about 2 days ago and its doin fine now

i replaced my fuel filter and the plug wires are pretty new and they’re ractive 8mm so i dont think they would have gone bad by now. im goin up to get the coil tested by autozone today ( they dont test ignitors for some reason) but if the coil is good im replacing the ignitor and if that doesnt work im gonna go ahead and get that 88 dollar diagnostic check done by acura. more ideas would be appreciated.

sometimes using a ;arger plug wire can cause that to happen too that what a friend of mines dad told me oneday and hes a certified honda tech

It is the ignition coil. Same thing happened to me with the A/F ratio guage going all the way lean, which threw me off for quite a while because I thought it was a fuel problem. Check the two resistances on the coil; I’m betting thats your culprit.

it was not the ignitor or the coil replaced both and still same problem. i had a b&m ajustable fuel regulator on it and it was helping it put out 38psi of fuel with the vacuum line attached so i found one that is a more high flow one , it took alittle thinking on how to tap it into the fuel rail but i got it done and turned the psi up to about 50psi with the vacuum line on. this fixed the problem but i dont know with it started doing it in the first place. and my air/fuel ratio gauge is still reading lean so im stumped. and yeah my ecu is spitting out throttle angle , fuel supply system( but that one might have gone away i havent checked yet), and the idle air control valve. im almost positive the idle air control valve is bad cause my idle is going up and down but i dont see where this would make my car run this way.