1994 Burb - consistent slight miss

[spyder2000]

1994 Suburban w/5.7L began missing at highway speed. Tach bouncing a bit as it did. It then began to stumble idle as well. It's got 207k and has been flawless.

Knowing ignition problems are easy to solve, I replaced the cap, rotor, wires and plugs with Delco parts. No difference at all. However, at cold idle I hear an obvious (to me anyway) tapping from the catalytic converter and this quiets as it warms (though it never does glow).

I am looking for advice, and for tonight I will pull plug wires one by one to see if I can isolate this to a single cylinder, and I will pump some fuel for examination and replace the filter (again, as I had a clogged one a couple months ago). Following that, I'll disconnect the cat and see how it runs at idle. I have no neighbors so they won't mind.

Thanks in advance for the advice found here.

[spyder2000]

Resolved.

[2000CAYukon]

Can you post what the issue was? This may help others who have the same issue in the future.

Thanks,
2000CAYukon

[spyder2000]

I apologize for failing to follow up on the issue I encountered.

The problem was that despite my best efforts, I had two ignition wires crossed. A 'newbie' mistake I should never have made.

To discover this, I drew a map of the distributor cap and followed each wire to its destination.