fuel gauge dont work and car sometimes jerks when driving

Believe it to have a fuel pump/sending unit assembly that replacing would likely fix both probs. Need to have fuel pressure tested to see if is in spec. Jerking could also be related to ignition misfire.

The jerking and the fuel gauge issue are likely unrelated. Sure, you could have a fuel pump issue or wiring issue causing fuel pressure problems and gauge issues. But it's unlikely. Still, have fuel pressure checked first to see if it's strong enough. Then have the fuel sending unit tested to see if it functions, or if you have a wiring or gauge issue.