2003 V6 XLT misfire
I can't figure this out, bear with me. We have an '03 XLT V6 2WD with 135k on the odometer. Recently I replaced the vacuum hoses (looked pretty dried out), spark plugs were replaced with Autolite double-platinums (though the old plugs could have just been regapped, I was in there so..)
This is a coil-on-plug setup.
The Escape will miss at idle (sometimes), miss under load (going up hill, for example)(sometimes). It will run fine when cool, or not, or run fine all day hot or cold, or not. Or it will do it when it's raining out, or not.
What's odd is that when the miss occurs at idle or under load, usually getting the revs up makes the problem go away (getting it to downshift, or if it's missing at idle simply pressing the throttle down and driving away).
In that scenario, once moving, there is no misfire and the Duratec pulls like a mule with it's tail on fire. When there is no miss, it idles and runs as smooth as can be.
So I have an intermittent miss, I'm down to swapping coils from one place to another, I broke down and bought a little OBD II reader. The last code was misfire on cylinder 4 at startup (which I understand is the cylinder towards the front of the car on the passenger side).
Anyone have other clues for me to follow? For testing, could I swap a coil in from my '00 Sable Duratec, are they the same?