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Testing Plug Wires

yes, you are testing for resistance. Ohms.

Rule of thumb is resistance should not exceed 5k ohms per inch or 100k ohms total.

Each wire has different length, so are you saying measure each wire and whatever inches each one is times 5k and that's what you should not exceed when testing with ohm meter?
And also each wire should never exceed 100k ohm no matter what. Right?
 
I just measured them and ohm meter reads between 2.88 and 5.30 on the screen when I select 20k ohm. If I am not mistaken this should mean 2.88k ohm and 5.30k ohm and the wire lengths are between 7 inches to 16 inches. (I have 4 cylinder engine)

So per this, I am well below 5k ohm per inch limit. Correct?
 
So per the above test and knowing that no spark is visible under the hood when observed in the dark, and no visible cuts or damage, can we say it would not be necessary to change the plug wires?
The current one is OEM motorcraft and couple years old with probably 25k miles on it.
Now Ford asks 80 bucks for a new one and it would be sad to throw that much money if the wires has no issue.
 
Plug wires having excessive resistance pretty much stopped in the mid 70s when catalytic converters became common. Ignition wires had to be improved for the health of the cats. When the core of the wire would break down, the offending wire had MUCH more resistance. It wasn't subtle. Today, plug wires are much more likely to have problems with voltage leakage at their terminals from mishandling or from contamination.
 
Well, I checked the Haynes manual and it doesn't say anything about wire resistance. It says if it is more than 2 years old with 30000 miles, it needs to be replaced. I wonder how many people out there change theirs at every 2 years.

There must be a way to test the wires. I am asking this because I feel slight missing at long stops while idling. It maybe happening while driving as well but I also have engine mount issues so I can't say for sure if it is missing. It may blend in there. Mine car is OBD I so it doesn't flicker the CEL when misfiring occurs. It is hard to detect sometimes. But whatever it is, it is not constant, mostly happens randomly. My plugs brandnew Bosch Platinum +4. Maynot be as good as Motorcraft ones but they should do their job. So if I can just make sure my wires are alright, I will move on.
 
Well, I checked the Haynes manual and it doesn't say anything about wire resistance. It says if it is more than 2 years old with 30000 miles, it needs to be replaced. I wonder how many people out there change theirs at every 2 years.

There must be a way to test the wires. I am asking this because I feel slight missing at long stops while idling. It maybe happening while driving as well but I also have engine mount issues so I can't say for sure if it is missing. It may blend in there. Mine car is OBD I so it doesn't flicker the CEL when misfiring occurs. It is hard to detect sometimes. But whatever it is, it is not constant, mostly happens randomly. My plugs brandnew Bosch Platinum +4. Maynot be as good as Motorcraft ones but they should do their job. So if I can just make sure my wires are alright, I will move on.

Get those Bosch +4 plugs out of there. Truly junk. This could be your problem. They don't work well with waste fire ignition systems.
 
Get those Bosch +4 plugs out of there. Truly junk. This could be your problem. They don't work well with waste fire ignition systems.

Are they really that bad? I was going to get 4 new motorcraft plugs last Friday and the dealer asked $8.95 for each one and I backed out. I will paying around $40 for 4 plugs. That's just insane.:shocked:
Well, maybe I will...
 
I found the Autolite part # 5364 and bought 4 of them from Wal-mart but when I got home, I realized that I got AP 5364 which means NOT double platinum. I will return them to get double platinum ones which will be APP 5364. It is going to be about $11-12 for 4 of them.
You sure these are equal to Motorcraft ones right? Because for some reason people scream at you when you use anything other than motorcraft plugs...
 
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