I have a u12 bluebird in my 98 200sx. When I start it up cold it idles fine but if I try and drive it barely hit the gas pedal the rpm will just break up and not want to go anywhere. I assume I have something up with plugs, wires. because i remember driving my car super rich and it ran fine without rpm breaking up. The things i have different in the engine is cams. Will spark plug gap effect the car when it is cold like .27-.28? The car warmed at normal temp runs for the most part fine with some slight bucking at partial throttle here n there sometimes. I know the jwt ecu runs rich, but the car shouldn't have misfire/broken up rpm if it is running rich. if i am really easy on it and have it get higher up in the rpms i am able to step on it more and it will be normal.

Let me know what you guys think.