I have a 99 accord lx 2.3 4cyl 5 speed. It has 235K and runs great but today after driving home on the freeway i hit a straight away at about 100mph to clean it out alittle and when i got off on my my exit the rpms were jumping from 800 to 3500 for no reason i checked all the hoses and throttle cables but cant figure it out. I am new to the honda scene usually drive a GM suv but w gas prices and a 46mile trip one way to work the accord rocks. Anyone please help me out, I would prefer someone who is a mechanic or a honda tech to answer me no offense to anyone who has been around the imports awhile. Oh yeah this is when the clutch is in or when its in gear and when in neutral just sitting.