to check your fitv........ !. take of your air intake tube. 2. locate the hole closest to the bottom of tb. 3. Start car up. 4. while the engine is cold put your finger over the hole to plug it and if you don't have suction, replace fitv. 5. let car warm up (let fan turn on). 6. put your finger over the hole again and if there IS suction then replace. Try both of these tests if either of them don't come out right REPLACE.