i have an 88 civi hatch with a b18 swap. while on the highway my speedometer started to jump then after letting off of the throttle it completely died. Now it reads 0 no matter what. how do i fix this?

 

You fix it by looking around and checking things out yourself. Then, you use the search function or get on the Google to search your problem...

There are a few avenues you could go down problem road:

VSS gear stripped...
Cable broke/popped out... (most likely)
Cluster went bad...

Yeah, that's about it... it's an EXTREMELY simple system.