VSS on my transaxle

The other day I was driving and I my speedometer starting going haywire. It would go up and down then the car started jerking alittle bit. Well the car has stopped jerking and my odometer and speedometer doesn't work at all. My question is I bought a new VSS and I'm planning on installing it today. But! Sometimes while I'm driving it the speedometer moves and it will tell me how fast I'm going and the odometer starts moving too. The check engine light will pop on when either meters aren't working but it'll shut off when it starts moving again. What is going on? Should I change the VSS with my car being so old or do I have a faulty wire problem? Its a 95 Honda Accord DX. If I install the VSS should this problem go away? Will my speedometer and odometer start working again? Or will I have to re-wire the whole sensor?