My car won't start unless i press on the gas pedal?

If your car has a carburetor, this is normal. If it's fuel injected, then it could be the Idle Speed Controller going out, bad sensor or clogged injector. There are injector cleaners that you can pour into your gas tank to clean that out. If you used one and it's still doing that, then it could be a bad sensor causing another piece to not perform correctly. Only way to be sure is to have a mechanic check out the sensors and/or the idle speed controller.