You can get injectors on ebay cheap..
You may have a vacuum leak as said above. I would snoop around with some propane to see if you can get it to run different..I did two of my 96's recently..So I can help with whatever you need. The stock intake system is flawed if you are going to mess with the injectors take the whole manifold off and redue with felpro gaskets and new valve cover gaskets..The intake bolts loosen up causing all kinds of problems. Both of mine were loose..The upper intake gaskets lose their seal..The injectors can be a bear to get off even with the intake on the bench never mind under the tunnel of doom. Injectors rarely go bad as a rule..Never had a bad one in 4 4.0l aero's or any car for that matter..Look for a vacuum leak..cyl no 5 is right near the IAC and the vacuum lines rear drivers side.
The intake job isn't a big deal if you are a mechanic and have the tools you need. If not it could be a challenge for sure. Its still fresh in my brain I could do a write up to save you the headaches.

Dick