Engine Crank/Engine Running
WARNING: This page does not describe the selected car, but rather 35 other vehicles, including the 2007 Mercury Mountaineer, 2007 Mercury Monterey, 2007 Mercury Montego, 2007 Mercury Milan, and 2007 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.
During engine crank the PCM fires 2 spark plugs simultaneously. Of the 2 plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs fire until camshaft position is identified by a successful camshaft position (CMP) sensor signal. Once camshaft position is identified only the cylinder under compression is fired.