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i bought some used NGK's and testing their resistance as the TSRM states: max. resistance of 25 k ohms. These are my readings: ranges increased from shortest to longest wires. shorter wires had readings around 1200-1300 ohms (note ohms not k-ohms).
Longer wires had around 3-3.9 k ohms (note longer wires in 'k ohms' now)
So is this good? Is "lower resistance" (lower ohm readings)good? might change wires and plugs today or tomorrow...for all i know the stock wires are from 1990
 

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Supra_DRE

guess a bit of a lesson is needed.

What is the prefix Kilo mean?

1000 right?

so that 1200-1300 OHMS equals to 1.2K-1.3K ohms :)

btw don't pay to much attention to the readings of the multimeters. The highvoltage in our ignition systems acts TOTALLY different than what the ohmeter does :)
 

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I've had plug wires go bad on my other vehicle, a '94 Stealth. The ohmmeter registered the resistance perfectly within spec for each wire... but when the 10,000 volts from the coil pack shot through it, the corroded insulation allowed the spark to arc to the block giving me nasty misfire.. from wires that measured exactly like they should have. Figgie's right they act very differently under high voltage...
BUT I tend to think resistance measurments on NEW wires won't be subject to this type of effect and are likely to be accurate.
 

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Nessus-GTE

high volatage travel on the conductor in what is called the skin effect. It actaully travel on the SKIN (aka the OUTER MOST part) of the conductor. The ohm meter actaully reads the resistance WITHIN the conductor. That is the reason why even in high voltage. A human body is a WONDERFUL conductor. As it travel on the skin of the person not internally :)
 

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Discussion Starter #5
figgie of course i know the 'k' in k ohm stands for kilo ohms.....like kilogram and kilometers LOL i just didnt know how to interpret the ohm readings for spark wires
 

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Measuring plug wire resistance with an ohmeter is the only relative method we can use. If the plug wires read a lower resistance at low voltage they will still read a lower resistance at high-voltage. Overall, your comparison of plug wires will still be valid with your ohmmeter. If you REALLY want to know how much lower the change in resistance is at high voltage we can calculate that. But I'm not going to.... here's a link with the formulae:

http://members.misty.com/don/skin.html

Trust me..thats not a porn site.. :)
 

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I heart 80's Toyota's
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my fav test for bad wires is to grab them while its running... if you get shocked.... well you need new wires


I actually had a set of wires on my 84 honda interceptor (motorcycle) that, when in the garage, at night, with the lights out, you could see the archs.... very bad wires
 

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haha i've done that test a couple times by accident :D. and yes lower resistance is better for wires or anything like that. resistance is just what is says, resistance to electrical flow. so the less the better.
 

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staticpat said:
haha i've done that test a couple times by accident :D. and yes lower resistance is better for wires or anything like that. resistance is just what is says, resistance to electrical flow. so the less the better.
from a purely electrical standpoint you are somewhat correct

but from a EMI/RFI supression you are DEAD WRONG.

why do you think that ALL the cars use carbon cored wires and not a solid metal core?

The EMI/RFI of a solid core wire would make the ECU NOT work at all!! :)
 

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There a few wire companies out there that have very low resistance with EMI supperssion. Accel 150 ohms & MSD Super Conductors 50 ohms. Both of these are ohms per foot. I haven't seen them for Supras though. And yes they are still good. For normal plug wires I use an 8K per foot rule. Anything over that is too much.
 

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MKIII87Turbo said:
There a few wire companies out there that have very low resistance with EMI supperssion. Accel 150 ohms & MSD Super Conductors 50 ohms. Both of these are ohms per foot. I haven't seen them for Supras though. And yes they are still good. For normal plug wires I use an 8K per foot rule. Anything over that is too much.
really?? :scratch:

once again. Ohm meter resistance doesn't mean shit.

i don't think it is going to get any higher resistance than that gap that is between the spak plug gap ;)
 

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This is a web page that talks about spark plug wires. If there is no reason to check the plug wires using the ohms setting on a DMM (Digital Multi Meter), why do all of the factory manuals have it listed? I guess all of the engineers are wrong then? Doing just an ohm test isn't all inclusve.

http://www.inct.net/~autotips/plugwire.htm
 

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MKIII87Turbo said:
This is a web page that talks about spark plug wires. If there is no reason to check the plug wires using the ohms setting on a DMM (Digital Multi Meter), why do all of the factory manuals have it listed? I guess all of the engineers are wrong then? Doing just an ohm test isn't all inclusve.

http://www.inct.net/~autotips/plugwire.htm
hmm

naw.. the engineers are NEVER wrong ***cough 52 lb/ft for head bolts ***cough*** :rolleyes:
 

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Just ran a test on mine ala TSRM, checked ign components, and all were with tolerance except the wires. 4.5k ohms on the wires, car's stalling, hard cranking, and contacts on dist are white(always get white shortly after cleaning). Should be getting some NGK wires tommorrow based on the searched I ran.
 
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