i just bought a 92 Si hatchback from a friend of mine. everything seemed fine for a couple days. today the tachometer went sketchy. it works fine when in neutral, responds to reving it up , but as soon as i put it into gear, it drops to zero and stays there. car seems to run fine otherwise, sound like its struggling a little when starting. i dont know much about how this all works, but im trying to learn. any help at all would be great... thanks