Could the throttle body be dirty enough to actually prevent the car from starting most times? That's the problem I'm having and trying to find a solution for (a lot of cranking and rarely starting).

 

I'm going to clean my throttle body when I install my WAI. My car sometimes (after warming up) will return to a really low idle when pushing the clutch in on a roll (goes to less than or close to 500RPM). The idle usually stabilizes after a few seconds but it has actually stalled twice because the idle went so low. Would putting a breather filter on the crankcase vent port prevent the throttle body from getting as dirty?