This is happening at low idle speeds. I guess you could call it sputtering. It sounds like a cough, then the motor seems to quit for 1/2 a second, then slowly revs back up to it's original Idle. If I'm idling slow enough it will stall. It always starts right up again.It also doesn't seem to matter if the engine is warm or cold, and whether not I'm running hard or just idling. Any ideas?