How to test plug wires?

[jayro]

Hi all,
I was wondering if there is a good way to test my plug wires. I have a set of Taylor wires which are pretty new. However, the vents in my cowl hood allowed rain to drain down into the plug wells. I was not aware of this and since the car is not a DD it sat that way for a while. Of course it didnt run right when I fired it up after a week or so. I found the issue and blew all the water out of the wells. There was a small ring of rust staining on the outside of the plug wire boots. I already replaced the plugs, but was wondering how I could test the wires to make sure they are ok. I googled it and found a recommendation that I ohm the wires to check resistance. If it is less that 2 ohms resistance than I am ok. Is this right? I can buy new wires if needed, but I don't want to spend the money if I don't have too......plus I like the wires since they are blue and match the car.

 

[vortex2450]

I remember testing my plug wire a while ago.

You want them to be around a resistance of 3kohm/ft. I remember mine longer ones being between 5 and 6 k ohms and the shorter one's around 4 ohms.

This isn't an exact as everything in the electrical world is basically an approximation. The biggest concern is you don't want no resistance (short) and you don't really want a resistance over 10k ohms on any of the wires.

I'm pulling this off the top of my head, I am sure someone else with more knowledge here will chime in. IF I was you I would just wire brush any corrosion off, test for continuity and resistance and reinstall. If it runs then you should be fine.

You'll know if a wire is bad when you have a nasty misfire.


-Josh

 

[jayro]

Thanks. I did have a high load/high rpm miss that was intermitant. Wasn't bad enough to throw a CIL, but you could feel it. It would pull hard, miss for a split second and then pull hard agian. Checked codes and there was a CID one. I am replacing the cam sensor....hopefully it is the cause.

To clean any corrision, is there an easy way to get to the metal clip that is up inside the insulator? Should I put any dielectric on the metal clip to prevent further corrision, or would this interfere with the transfer of current?

 

[frosho]

I believe you're supposed to use grease where the boot contacts the ceramic, but you don't want it on the contacts themselves. That way you have a good electrical connection, and the bottom of the boot is sealed from the plug well. The boots themselves aren't perfectly sealed though, so if you get enough water in there, they will still short out.

 

[itwonder]

One good way is to inspect in a very dark garage while the engine is running. A plug wire arcing is pretty easy to see.

 

[mrecoolgar]

I checked a nos set of Motorcraft wires a while back to use as a guideline.
Here are the specs in Ohms.
1 = 10.0
2 = 8.0
3 = 7.0
4 = 8.0
5 = 4.5
6 = 4.5

 

[kevinspann]

Resistance of a maximum 7000 ohms per foot is the spec, I believe.

 

[Phoenix]

Just so you know , I have tested other brands in the past , tested good but the wires were still bad.

It helps but its not 100% trustworthy.

For 100% you need to swap with another good set when available.