Ive got a 97 accord LX four banger. Tach started jumping while driving on the highway. Would be fine, running 3k and then bounce up to 4k. Didn't notice any change in engine or driveabilty when this happens. About 30 minutes later tach went down instead of up and the car jerked like a bad miss. Now happens about every couple of minutes.

Any ideas? Car runs fine when tach bounces upward. If tach bounces downward, car misses, jerks, stutters, . .. .whatever. Can't recreate when idling or reving car at a stop.

No check engine light. Anyone know whats causing this?