THE HOSE IM TALKING ABOUT IS VISIBLE IF YOU REMOVE THE AIR INTAKE TUBE THAT CROSSES THE TOP OF THE ENGINE AND LOOK STRAIGHT DOWN BESIDE THE THROTTLE BODY..(YOU MIGHT NEED A FLASHLIGHT.. THE HOSE IS ABOUT 3/4 IN ROUND ON ONE END WHERE IT PUSHES ONTO THE TOP OF THE ENGINE AND ABOUT 1/2 IN ROUND ON THE OTHER END .. THE HOSE IS ONLY ABOUT 6 INCHES LONG ALLTOGETHER.. SORRY I CANT USE MORE TECHNICAL TERMS BUT MY CAR WAS DOING EXACTLY WHAT YOU DESCRIBED ABOVE AND I TRACED IT DOWN TO A CRACK IN THAT HOSE.. WHEN I REPLACED IT THE IDLE AND EVERYTHING SMOOTHED RIGHT OUT.. BENJAY