First post everyone, i appreciate the help beforehand. I have a 92 si with a h22a3 swap. Car has been running fine but just a few days ago after a road trip it started acting up. It idles fine but when i drop the pedal the car gets up and goes but gives a thump on every rotation exactly as if i have a flat tire. But when you take the car out of gear and let it roll its fine, i just got new tires a week or so ago its not the suspension. I was thinking possibly the motor mounts or axle?? Any ideas anyone? Thanks again.