I have an automatic 1994 Civic EX with a stock D16Z6 and every once in a while it wont start. The car cranks but it wont start, Sometimes it feels like it wants to start but then chokes. The only way i can get it to start is if i push the gas pedal down when im cranking it. When im cranking it and push the pedal down to start it, i can smell the smoke coming out of the exhaust. Any common problems this could be?