1993 240sx bucking, won't rev

[nismo521]

This morning on the way to work, my 240 started to buck just as I was pulling out of my apartment complex. Just after it bucked, I tried revving and it would not go above more than 3800 rpm. It didn't bounce off of 3800 like it was hitting a limiter, it just simply revved to 3800 and stayed there. When I stopped at the next light, about 300 ft. later, I tried revving again and it went all the way up to redline w/o a problem. The car drove fine w/ full power (well, as much as it can have w/ the A/C on) and no more bucking for the rest of the trip. Any ideas as to what can be causing this problem? I'm already planning on testing the ECTS and running the codes to see if it could be the knock sensor, but any other ideas would be greatly appreciated. Thanks.

[rotorimp]

If it happens again try and isolate a cyl. by pulling off the injector leads one at a time--sounds like one of the injectors got stuck.