You may have a vacuum leak, get a can of spray gumout, spray the vac lines and maniflod area, when the idle changes, youve found the leak! You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs! If that doesnt do it, This can be a fire hazard if you spray onto the hot exaust manifolds. You may need a new idle air control valve, it's bolted to the throttlebody
Pay particular attention to the PCV rubber hose, these tend to dry rot on Fords, may look good, but the crumble when touched, and vacuum is lost thru them.
Saturday, August 14th, 2010 AT 7:35 AM