Check the fuel pressure regulator (right on top of the fuel rail behind the alternator). Mine caused hard-to-start and rough idle situations.
Rough idle or high idle can come from vacuum leaks. These engines have vacuum lines all over the place so it's easy to have one come loose or been removed by previous owner. The TSRM has a good diagram plus a Google search will turn up some other detailed diagrams. I hunted a loose vacuum line for nearly 3 months!
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