Misfire Issue Options

[PaukST]

So, about 3 weeks ago my 94 ST started getting a misfire. Initially, it was only under mid-heavy load, like going up a hill at relatively low revs. I replaced the spark plugs and it got better for a few days, then went back to the occasional misfire. However, a few days ago it suddenly got way worse. I pulled up to a stoplight, but when I went to take off, it would barely go. It's nearly undrivable. It's pretty much a constant misfire now. It seems to be cylinder #2. It tries to die if i pull a spark plug wire/unplug an injector from 1, 3, or 4, but nothing changes when i unplug either from cylinder #2.

I had changed out my spark plugs and wires probably less than a year ago. I rebuilt this engine June of last year, and have had a VERY slight miss with this engine all along. I assumed it was due to the ever-worsening crack in my exhaust manifold (located closest to the cylinder #2 exhaust port).
So:
---Rebuilt 18 months ago
---Replaced spark plugs about 2 weeks ago, the old ones weren't broken or particularly noteworthy
---Replaced spark plug wires within past year
---Switched over the injectors from my other 7A-FE thinking one may have been clogged, no change

Anyone have any ideas? Advance tells me they can't check the CEL code on anything pre-96.

Second edit to add that I replaced my distributor cap/rotor around the same time as my spark plug wires. I took the dist cap off today and cleaned up the contacts, they looked fairly bad again. Unfortunately that changed nothing.

This post has been edited by PaukST: Dec 12, 2013 - 6:15 PM

[DeviantCorndog]

You also said your Distributor cap was dirty again which also isn't a good sign what kinda of dirty was it. This may help.

The major defect found in distributor caps and rotors is carbon tracking.Moisture that accumulates inside the distributor causes spark flash over inside the cap, which produces a path of carbonized material between two of the cap terminals. Carbon tracking in the cap frequently causes a constant engine misfire. A carbon track looks like a dark line in the cap. The rotor may also develop a carbon track under the rotor input terminal due to high-resistance or old plug