I recently bought a 92 civic hatch with a b18a1 with a grs head, and the ls intake manifold. I recently blew a coolant line, the U shape one on the back side, and ever since then, when I'm driving the car, it will start to stutter when I'm holding the car a steady speed. I dont remember a time this has happened under 3000 rpms. the stutter can be heard, but felt much more. when this stuttering is happening, the rpms dont fluctuate any more than normal. again, this is only happening when I'm maintaning a speed, if I press the gas even a small amount it goes away, and if I'm off the gas completely and decelerating it doesnt do it either. its becoming more frequent, and now when I accelerate, not hard but just for normal driving, it stutters once to 3 times around 3600-3800 rpms, not as hard either, but noticable. we changed the fuel filter, the fuel dumped out of it was pretty ugly, and looking into the throttle body, there was a lot of carbon build up and we cleaned that out pretty well, and its still doing it, but at random, usually it will either do it from the time I start the car, or not at all, and will often do it the whole time the car is on, so random trips to say. and now the most recent ad on, only after the car has been driven for a while, when idling out of gear it fluctuates from 1000 rpms to 1300 rpms in a slow cyclicle pattern, the cycle lasting about 2-3 sec I'd say from 1000 up and back down. stock injectors I believe, and something else mentioned but we thought unlikely, 7mm plug wires. but as I said we were thinking now it might b the tps, or my injector are clogged? any input is great appreciated.

another thing, my friend was sitting in my car unsupervised, and has a problem with touching things, in the mean time, he changed the display, and when trying to get it back, somehow set it so the vtec doesnt kick in, and i dont have the manual, since it was installed when i bought it, and the previous owner didnt have it either. thnx
-chad

 

i had a very similar problem, turned out to be tps

 

b18a1 with a gsr head? ok lsvtec but you cant fit a ls intake manifold on the gsr head. u sure its not a gsr manifold?

 

Check your basic stuff first like spark plugs and wires. I've had stuttering issues around the same rpm range as you and changing my wires and spark plugs did the job.