strange lag

Swapped a b16a into a 91 crx si last week, worked out most of the bugs but im still stuck with one. when I am maintaining speed in any gear at any speed the engine will slowly begin to lag sort of as if one of the cylinders isnt quite firing right until I push the gas pedal more then it jumps and runs fine for 5-10 seconds then starts doing that again. It is progresive, and the only thing i can think of is the fuel mixture is not being adjusted while maintaining speed. It accelerates fine and runs good when im running it hard this is only an issue when maintaining speed, the slower the speed the worse it is. it also has a somewhat erratic Idle, usualy it is idling below 700 and rarely it idles above 1000, both when warmed up. I have adjusted the throtle cable once to up the idle and have refrained from doing it again till I figure out this other issue.
Thanks to anyone who takes the time to think on this.

clogged fuel injectors?

when was the last time you used fuel injector cleaner?

first tank of gas with it in, already emptyed that tank. I have been thinking it is a vacum diaphram that is sticking unless it gets a significant pressure change??

your not getting any ECU codes?

No Codes at all, Im suspecting the TPS.