Fuel and Ignition Fuel Pumps and Systems, Ignition and Spark Systems

OHM Test plug wires ?

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Old Feb 23, 2009 | 06:35 PM
  #1  
600hplt1sm's Avatar
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From: Hagerstown, Maryland
OHM Test plug wires ?

OK, I removed all my wires today because the car runs like JUNK to say the least. At idle sitting it sounds fine no misses everything is great, As soon as you put in gear and start to move it feels like a tractor trying to move, it is misfiring, there is a more than normal vibration and you really have to get on the gas to make it move but it sounds terrible.

I just changed the plugs, did the fuel system in parallel. So i figured i would test my plug wires. I was using MSD 8.5 wires here are my results

1 32" 12000 on the meter
2 36" 13000
3 42 16000
4 41.5 16000
5 49.5 19000
6 49.5 19000
7 51.5 20000
8 56.5 21000

coil wire 22.5 11000

Now my question is the # 5 wire is burned through the outer covering and cracked on several places due to heat from the header. But since the ohm test shows the same number for # 5 & 6 does that mean the # 5 wire was not comprimising the system or do you think it was the problem,

These are a OTVC setup & I had to crimp them myself. Today I ordered a set of Magnacore wires @ a nice price of 229.00. I need to figure something out for #5 thats the only one i have a burning problem with.

So I guess my question is regardless of the numbers could the #5 wire be bad

Last edited by 600hplt1sm; Feb 23, 2009 at 06:38 PM.
Old Feb 23, 2009 | 07:37 PM
  #2  
Green96Z's Avatar
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From: CA, home of the smog nazi
Replace it. I slightly burned one of mine (not even through the first layer of insulation) and I had a bad miss. Call MSD, they will send you a replacement wire for free.
Old Feb 23, 2009 | 08:11 PM
  #3  
MikeGyver's Avatar
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From: Orem, UT
I got curious the other day and used a nice Fluke meter to measured the resistance of some MSD Superconductor 8.5mm spark plug wires.
I was consistantly reading like 85 ohms per foot while the normal style Accel wires I tested were in the kilo-ohm range. Very impressive for a spiral wound plug wire.
Old Feb 24, 2009 | 05:29 AM
  #4  
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From: Hell was full so they sent me to NJ
Those numbers look way high for the MSD's.

When you measure the resistance (ohms), you are measuring the conductor's ability to carry current. You are not measuring the viability if the insulation, and its ability to insulate the 20-30,000 volts that the wire is carrying. You could have ideal resistance in the wires, and a small cut would destroy the insulation and make the wire useless. The fact that #5 has the same resistance as any other wire has nothing to do with whether #5 will spark when its close to a grounded surface.

If the insulation is damaged in any way, the wire is compromised and needs to be replaced.
Old Feb 24, 2009 | 07:41 AM
  #5  
600hplt1sm's Avatar
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From: Hagerstown, Maryland
Thank You, thats what I was looking for. As for the numbers I had the ohm meter set on 20 K so thats why i put down the numbers in the thousands. So maybe I should have set it on the lowest setting which I think is 2. Either way thanks again. I hope this was the problem
Old Feb 26, 2009 | 04:39 PM
  #6  
shak180's Avatar
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rule of thumb is 10k ohms of resistance per foot of plug wire
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