Ross - It sounds like you are describing the Contour that I'm working on.
Here's my origninal post.
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=698015&page=&view=&sb=5&o=&fpart=1&vc=1 (Sorry, I don't know how to make the address any shorter.)
When I finally put a vacuum gauge on my motor and saw 8" of vacuum, I figured it was something serious and started tearing the engine down. I am now suspecting (like you) that one of the timing chains has jumped a tooth or two. When I pulled the UIM, like yours, the rear banks ports were dripping with fuel, while the front banks were black from running rich.
My theory is that the front bank is running okay (and the cam sensor drives off the front bank so the ECM figured out which order to fire the injectors in). But I think the rear banks chain has slipped, causing the rear banks to blow the injector spray back into the intake track (thats why the rear LIM is dripping with fuel) and what does go out the exhaust valves of the rear bank hasn't been burned so the O2 sensor 'senses' the oxygen (since it hasn't been consumed by combustion) and tells the ECM, which in its wisdom then drives the injectors rich, which is why the front bank is black with carbon.
I'm gonna try and get the cam covers off tomorrow to check the timing chain marks to see if my theory proves correct, but I have some questions re: the timing marks - see my last post at this site:
http://www.fordcontour.org/fcoforums/showthread.php?t=4125If you have any ideas, I'm all "ears".
