2003 Mercury Sable Cold Engine Misfire

[Mickey Toombs]

My 2003 Mercury Sable w 3.0L 24V Duratech engine misfires in cylinder #5 only at cold start-ups. The PCM sets trouble code #s P0305 & P0316. After the engine warms up for a few minutes, the misfire disappears and the engine runs great during all driving conditions. The trouble codes can be erased after engine warm-up and will not return until the next cold start. I have replaced the following to date: spark plugs, plug wires, coil, intake manifold gaskets, #5 cylinder fuel injector, & the TPS. I have also performed cranking compression tests on cylinder #s 4, 5, & 6 (easy to reach) w/ acceptable results. I have not replaced the camshaft or crankshaft position sensors to date, but they will be next. Any ideas or information on a similar problem would be greatly appreciated.

[danielsatur]

1) Roll COP #5 with COP #6.

Fire wall
1 2 3
4 5 6
Coolant fan

[Mickey Toombs]

If the term "COP" stands for coil on plug, it doesn't apply in my case. My 2003 Sable has a single coil assembly to fire all 6 cylinders and I replaced it.

[temperingloser]

I have a 04 sable that was having no starts when it was cool and sometimes intermittent dieing never threw any code but come to find out it was just the crankshaft position sensor only found this out due to having to take it to a dealership because I could not figure it out. I had the sensor at my house but never had the time to put it in figures!!!! you may start there it is not that expensive