My 98 honda accord ex will sometimes not crank, and when I do get it to I have to flood it with gas just to keep the rpm over 1 because if I don't it will just decelerate and cut off. It also will stall if I let the car idle on its own, without me gassing it and keeping the rpm over 1. What could it be? I have already replaced spark plugs, battery, oxygen sensor. I have also cleaned the idle air control valve.