03 cavalier speedometer went to 0 car jumps then dies and starts back up

Repair shop's take men just as much. Have it read for codes, even if the check engine light is NOT on the computer will have stored information and codes. Discount auto stores will read codes for no fee. write them down.

You may want to check for bad negative ground wire, if engine and speedo/instruments are dying at the same instant. A bad cam or crank sensor losing signal could trigger an engine shutdown, or bad powertrain/engine control module or automatic shutdown (ASD) relay, but none of those would instantly kill a speedometer. Yours is most likely electrical related. The fact it starts right back can be due to a bad intermittent ground, a frayed or loose terminal on the battery cable etc. Wiggle those cables around, if you see any that look suspect, replace them. Someone with a volt/ohm meter can check for continuity.