2007 Scion tC Starting Problems

You turn the key to start it and it makes a "click, click, click" noise. (It doesn't always do it) After the first try sometimes on the second try it will start right up, other times it will do the clicking noise again. Sometimes if you try turning it on and press the gas it will start up, but not always.

Replaced the gas tank filter and cleaned the air flow censor.