[scottfab]

Well well well.... that was a novel. I just read all posts from the beginning to the most recent.
I had heard about this thread a couple of years ago from Jeff Flint and very sorry to see it is still active.
Let me toss out my thoughts and story.

I fought an illusive problem on my ZR1 in 1998 after having the car for about 2yrs. I drove it to the midwest and back and it developed this stumble on acceleration. As a result I ended up developing a pattern check jig for the injectors after studying the data from my scan tool.
(Diacom). No good, still stumbled so I bought RC injectors (not a mistake because of the stainless steal construction of the RC) still had the stumble. I bought a spare ECM (not a mistake as it turns out cause to pass the state inspection it is easier to replace the ECM than the chip, and safer) still had the stumble. The fuel pump #2 then failed (unrelated problem) still had stumble. I then developed an emissions problem which after much searching turned out to be the CATS. Returning to the search for the stumble I next replace the coils. Fix! It toot took several years of slowly going at it. The only difference in my case is I would drive it anyway even with the problem. That is what uncovered it since eventually the plugs told the story. I learned a LOT about the car and reading the scan data.
I hope the coils fix it !!!

PS. I am going to toss my bosh/platinums ...... I just checked the plugs as a result of reading the thread (novel) and #3 was fouled. I put in a used AC plug (since I keep spared of many many working parts) and the fouling stopped........hmmmm)