I recently bought a 1994 mustang gt 5 speed, car had a rough idle when I picked it up but figured I could fix her. Yesterday on my way to work it started misfiring. My short term fuel trims are showing me bank 1 is running very lean. Before the misfire I just replaced the cap and rotor and my plugs are in good shape. Yes my plug wires are correct. I checked with brake clean and I can't get a vacuum leak to present itself. There is minor rodent damage in a couple spots but no exposed wire and I can't get anything to change via a wiggle test. Also my electric fan is running on low full time. Replaced my coolant temp sensor and no change. Any ideas on what's going on?