ok i put a 94 jdm h22a in my 90 accord ex, i took out a/c p/s and c/c i have a hesitation at about 2700 and lasts usally to 3400 or a little lower, i just changed my plugs and frequents oil changes, it has done this since i put the engine in just not as bad as it has been the last few days, i recently put in a msd blaster coil also because i had to change my cap and rotor and jdm is internal so i had to change it to external, anyhow when i first got the engine they gave me the wrong ecu it was like a p29 or something it was for a sohc vtec accord in japan but no speed shop or honda dealer knew what it was from i found it on the net, it did kind of bog out then to, then i got the new ecu and i threw a knock sensor code but because i forgot to hook it up so everything is basically fine now but the hesitation any help at all would be greatly appreciated, cause im completely stumped on this one. i also do not have my sensor wire for my oil pressure hooked up if that does anything at all ive been planning on doing aftermarket.
i also have a really low idle like at 200 or 400 i think hard to tell with the white guage faces i have but its got to be 300 or around

 

Sounds similar to the problem I had. It turned out that it was my timing. You probably just need to adjust your distributor.

 

Sounds like cam hunting. The cams are looking for a sweet spot in that rpm range and when they find it, it kicks in. play around with your cam and ignition timing.

 

Make sure your knock sensor is good. A lot of people have this problem and someone just solved theirs by replacing the knock. I'm going to order one on MOnday to see if it helps mine.