I belive i have a vacuum leak...my stangs rpms fluxuate when it is sitting still it will range from 600-1000 whate else could this be? also my cra sometimes take 3 or 4 times to start...i changeed the fuel line and filter because thats what someone suggested and i do not think its teh started how do i go about solving this?

 

The Idle Air Control valve probably needs cleaned or changed.You can clean this fairly easily and clean the rest of the intake system as well by using a can of spray carb cleaner.Start by removing the hose going into the IAC and sliding the straw from the spray can into the hose.Now replace the hose and plug the straw into the can nozzle.Start the engine and spray the cleaner into the intake.Keep the engine running by using the throttle blade crank on the throttle body.
This will cause a lot of white smoke and you can use this time to look for exhaust leaks also.

 

check spark plug wires mine wasnt on all the way and made my rpms jump about 300 rpm