I have a 91 MR2 N/A when i am driving and I'm in a low RPM( under 1500rpm's) I experience a forward bobbing motion( I am not giving it any gas). I would describe it as someone putting their feet on the back your chair and slowly extending their legs and retracting them. It happens a lot in rush hour. It it rather annoying. My clutch is dead and my car is sitting motionless now. I plan to do a repair before Christmas. Things I'm thinking it may be: Warped Fly Wheel, Fuel Injectors, Oxygen Sensors or maybe something clutch related. I don't thing it is spark plug related because they are rather new. Any Ideas, please post.