Hey guys, I just bought a 90 Nissan Sentra XE for commuting. Relatively solid car, 80k-ish on a rebuilt engine. Car runs and drives well but after 45 min or so under "normal" rpms (no tach or else I would supply exact numbers) the engine will start to surge, so violently that it will buck the entire vehicle (as if someone new to driving a stick wasn't giving enough gas). But if you keep the rpms pretty low, the car will run smoothly. You just can't run out the gears like you should be able to. Anyone know where I should start looking to remedy this? Thanks
