 Engine Runs Rough - poor Acceleration
Short Story: Last Friday I started my 2002 F Focus SW and found it idling very rough, it has trouble accelerating, just when the engine starts to run better it shifts into higher gear and poor acceleration starts all over again.
More Details: bought used in 2004, engine has never been a problem until fairly recently (jumpy rear end and shimmy in front end at 60-68 MPH were the problems) but about a month ago I was on a long trip (400 miles RT) and at one point I had this same sort of rough running engine...I shut off the engine and everything reverted to normal. Then about a week before this rough idle/running problem surfaced, I was coming home and noticed a strong exhaust odor inside the passenger cabin...I thought, oh don't tell me I have to replace the muffler or exhaust system...well that also went away the next day. BTW, I don't drive every day and I was hoping for some dry weather to allow me to crawl under and check things out...I'm not Mr Goodwrench but I do what I can to do my own maintenance. Then like I said, last Friday, (1 week as of tomorrow) I hopped in to go to a job search group meeting and didn't think I would even make the meeting at all, it was barely running.
Auto & Engine Details: 2002 Ford Focus SE Wagon 4Dr, 4 Cyl, 2L, 16-valve Zetec Engine, Auto Trans, between 74-75,000 miles.
Misc: The only other problem I've had with this vehicle aside from the Bouncing Rear End and 60MPH Shimmy is that the AC Fan stopped working on 1-2-3 Speeds, it only works on 4 Speed and then it turns OFF the AC, just blowing whatever temp air is in the blower, however the AC COOLING ACTION still works when I set the blower speed to 1-2-or 3, but the Blower won't blow the cool air.
I am wondering if the engine problem is (1) Fuel injector, (2) Bad Spark Plug or Wire, (3) Bad Electronic Ignition or Distributor cap, or (4) Timing Belt problem.....or something I haven't considered. All HELP greatly appreciated. | 
