my 1987 z28 305tpi 5speed the RPM gadge dont work right when you start the engine the RPM idels at like 6,000 rpm you barley give it any gas and it max out... IS IT A SPEED SENSER or what lol????

 

1) Please communicate to us on a level slightly higher than 3rd grade grammar. Seriously man, how do you expect us to take you seriously when you cant even spell gauge or idle?

2) 6,000 RPM? Most SBC's would blow up around 5 grand.

Give us an intelligent assessment of the situation and we would be more than willing to help. It does sound like a sensor. Have you tried any other diagnostics? (other than staring at the engine...)