Plug wire resistance

[Randy S.]

My 66 300HP 327 was running a little rough the other day which got me to thinking about plug wires. I measured the resistance today. Wires 1 thru 4 were 13.5K to 16.5 K. The shorter wires 5 thru 8 were 8.8K to 10.1K
The archives suggest 2000 ohm per foot and Bill Clupper says the GM spec was under 25K is OK.

Wire #4 was odd in that the value would never stabilize on my digital VOM fluctuating between 15K and 17K. Maybe operator error.
The wires are AC Delco dated 3Q88!! wow almost 20 years in there. So what is the consensus should I replace them?

I haven't removed the spark plugs. As much trouble as that will be on my AC car I'll just replace them rather than inspect and replace.

BTW the rough running dissapeared next run out... maybe bad gas

Randy

[Gerard F.]

Re: Plug wire resistance

Randy,

If you are 13.5K to 16.5K on the 1 through 4 wires, I think you are good to go. The spec I think is 5000 ohms per foot.

The least I got out of my Lectric Limited crap was 18.1 K on the 48" ones. The 45" one was anywhere from 30K to 120K depending how you connected the ohmmeter, and how you manipulated the wire. So I knew it was bad.

After my recent experience in changing the plug wires, I would never recommend those Lectric Limited repros for a driver. 3 out the 8 were out of spec.

If you ever get that miss again, pull your plugs and inspect them, the bad plug wire will show right up.

[Duke W.]

Re: Plug wire resistance

Buy the Delco 508N set and just replace the #4 wire and see how it runs. You can probably swap the red boot for the old black boot. Use a small screwdriver to pull the boot away from the wire inject some silicone spray lub.

Keep the others as spares. Depending on how much you drive they could last another 20 years.

A non-stable reading indicates there is a problem with the wire. The reading should be stable, and it's best when checking resistance to move the wire around to be sure the reading is stable.

Duke

[Randy S.]

Re: Plug wire resistance

Duke and Jerry,

Thanks for the input. I decided to look at the #4 plug because of the questionable ohm reading on the wire. Of course #4 is under the AC compressor. I am still bleeding...Anyway #4 looked good, tan insulator, no crud on the electrode, etc. Plugs are 45S.

I'll rule out plugs an wires for a while

Randy