Testing plug wires - can I do this with a multimeter?

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Aug 15, 2002 | 10:10 AM

nanotech

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Testing plug wires - can I do this with a multimeter?

Anyone know what the resistance should be for 30V plug wires? I assume "close to zero" but how would I tell if I have one out of spec?

Aug 15, 2002 | 10:28 AM

Dolmangar

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Compare them to each other, usually you'll find one that is way off.

If they are all about the same, then at least they are wearing out at the same rate.

Aug 15, 2002 | 11:25 AM

ArandA4

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Actually, not close to zero.

I have the 1.8T, so I don't know the year/engine code correlation for the 2.8. That being the case, here's both.

- Pull the ignition wires from the spark plugs.

- In order to perform a resistance measurement, connect multimeter between both spark plug connectors of the respective ignition circuit to be checked. i.e., resistance between coil and 2 wires.
ATQ Specification: each 16 to 27 kOhm
AHA Specification: each 18 to 25 kOhm

- If the specified values are not reached, disconnect ignition wires from ignition coils and perform a separate resistance measurement at the ignition wires and at the ignition coils.

- For ignition coil, connect multimeter between both ignition wire connectors of the ignition coil to be checked.
Specification for both AHA and ATQ: 8 to 14 kOhm

- For each ignition wire, connect multimeter between both ignition wire connectors of the ignition wire to be checked.
ATQ Specification: 3 to 7 kOhm
AHA Specification: 4 to 6 kOhm

- Replace faulty components if the specified values are not reached again.

Aug 15, 2002 | 11:35 AM

nanotech

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I thought the 30V didn't have coil packs. Are they saying measure through the coil...

to which all 6 connect?

IE I remove all the wires from plugs, and measure resistance between, say, wire 1 and wire 2? 1-3, 1-4, 1-5, 1-6 and repeat with 2, 3, 4, 5?

Which piece is the ignition coil on a 2.8?

Aug 15, 2002 | 11:51 AM

Kris Hansen

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between 4 and 5 k ohms IIRC..

Aug 15, 2002 | 11:53 AM

Kris Hansen

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Each PAIR of wires has an ignition amplifier (coil). Measure the resistance across the whole deal..

Aug 15, 2002 | 11:55 AM

ArandA4

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See if this helps...

<center><img src="http://home.earthlink.net/~andrewaranda/audi/coils.gif"></center><p>
Like Kris says, there are actually 3 coils, each feeding a pair of wires. You'll have to measure resistance from the tip of one wire to the tip of the corresponding wire. If that whole combination is out of range, then break it down into individual wires and/or coils.