Well, I'm up and running again. Thanks to everyone who kept the ideas coming. I'm not an ace mechanic, but not that bad, either. This thing fooled me, though.

When it went bad, I had just run through 1st and 2nd gears pretty hard. When it immediately began running bad, I thought I had done some damage to the engine, probably valvetrain-related. I checked the header primary tubes with my infrared heat gun and found that #3 and #7 were about 250 degrees cooler than the others. I put an inline neon tester on those 2 wires and got an indication of spark, so I still thought I had broken something.

Everything I checked, however, looked fine. Like (#8 poster) Infletcher, I did not believe that plug wires would go bad that suddenly. Admittedly, they were long past when they should have been replaced, so I ordered a good set of wires online.

While waiting for those to arrive, I began checking the old wires with an ohmmeter. Depending on the position of the wires, #3 and #7 would sometimes measure open. Apparently, bending them around to hook up the tester in the car caused them to test OK, sending me looking elsewhere.

In the 13726548 firing order, the #3 and #7 are adjacent cylinders and this made a pronounced miss in the engine. Poster #7 (Chanmadd) had guessed it was the wires, and it was. Taylor makes a really good plug wire. I would be ashamed to tell you how long these have been in the car. I just left them in too long.

The engine is fine. I just left those wires in for 'way too many years and then was unable to diagnose the problem because I, also, didn't think plug wires would go bad suddenly. My bad.


Thanks for the input, guys.

Glad to hear
 

Always very satisfying to stick with it and get these things resolved yourself! You could always flatbed it away have it diagnosed and fixed but you don't learn that way...well done.

Cheers
Steve H
SPF 1764

Losing one half of the engine in FIRING order, not left or right bank.