Gas gauge goes to full, then drops to empty on 1995 BMW 318ti

when I turn on the car, the gas gauge shoots to full and then drops to below empty and does not allow the car to turn over. what could this be? and how much should it cost to fix?

Asked by for the 1995 BMW 318ti
It sounds like you have an electrical problem, possibly a short some where. Finding a short is a step by step process of eliminating 1 circuit at a time. It could take many hours or 5 minutes if you get lucky.
1 more answer
get some gas