# Miss



## nap (Dec 4, 2007)

help me out here. How many coil packs does your car have?

3 with 2 plugs to each one?

and you can do a basic resistance test but that is not that dependable.


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## rusty baker (Feb 13, 2009)

I think it's one with all six wires running to it. Too dark and raining to go look again tonite.


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## nap (Dec 4, 2007)

a quick search for parts shows that it uses 3 coil packs where 2 cylinders are fired by each coil.
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http://www.autozone.com/autozone/parts/1989-Buick-Regal/Coil-Ignition/_/N-ih3oaZ9n80r

http://www.autozone.com/autozone/pa...icleIdForService=112077979&_requestid=1065861

you can check the windings with an ohmmeter and since you have 3 of them, you can compare each one to the others. You can also swap the 3 around to see if the miss follows the coil or stays with the cylinder.


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## rusty baker (Feb 13, 2009)

It's this one.http://www.autozone.com/autozone/ca...62-0&itemId=27-10&store=2333&productId=367748


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## nap (Dec 4, 2007)

did you notice that the blue square above the part picture says:

the part you have chosen does not fit your vehicle


when you click on the link that says "find parts that fit" it shows the one I linked.

and that coil is only $50. Dang, a friend has a Ford truck that has 8 coils on it and each one is about $100. For $50 I would just replace the thing. 

If you can find the resitance readings for the windings, you can check that. It often does not show marginal problems though.


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## rusty baker (Feb 13, 2009)

Part # C860 is what comes up for a 1989 Buick Riviera. Single coil.


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## nap (Dec 4, 2007)

do you have an 89 Riviera? You had looked up a Regal in the first link you provided. I see now it is changed to a Riv.

anyway,
If I remember that unit correctly, you can check the resistance in the windings. That unit is essentially 3 coils put together (I believe as opposed to 6) as 2 cylinders are fired at the same time. You should be able to compare the reading between the 3 units within.

Other than that, not much to check.


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## rusty baker (Feb 13, 2009)

Had you ever heard of a coil pack, where one stud didn't fire?


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## nap (Dec 4, 2007)

rusty baker said:


> Had you ever heard of a coil pack, where one stud didn't fire?



yes.

as I said, I believe there are essentially 3 coils in that one pack. The windings of any 1 of the 3 could go bad.

I saw a little tool recently that was more or less a couple electrodes with a gap in between them. You put it it inline in the plug wire and you could view the arc. While it didn't measure anything, it allowed you to compare the spark, to some extent, between all the secondaries of the coil.

Short of that or putting it on a scope that can show the output of each of the coils, not much of a way to make much of a determination. The cost of a diagnostic scope is going to outweigh the cost of the coil pack. No idea what that little tool cost and sorry, but can't remember where I saw it other than it was online somewhere.


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## rusty baker (Feb 13, 2009)

I changed the coil pack. One section underneath was melted. It's better, but it's still running rough. More work to do.


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## rusty baker (Feb 13, 2009)

The new coil pack is dead on the same 2 cylinders as the old one.


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## nap (Dec 4, 2007)

rusty baker said:


> The new coil pack is dead on the same 2 cylinders as the old one.


and still no codes via the OBD? Did you clear the computer the last time you read the codes?


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## rusty baker (Feb 13, 2009)

The computer has never shown any error codes. I can pull the wires off the coil with it running, insulated spark plug pliers of course, and there is no spark. Exact same thing as the old coil pack. It had a melted spot between those cylinders. It wil be tomorrow before I can pull this coilpack off to see the underneath.


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## 47_47 (Sep 11, 2007)

Take a wire off of a spark plug on a missing cylinder. Connect it to an extra spark plug, ground the base and check for spark. Check the resistance tower to tower of each coil pack and compare the readings. Not too many tests to do without specialized equipment, this is one case where either you take it in to have it properly diagnosed or you become a parts changer. You may also have a bad module.


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## rusty baker (Feb 13, 2009)

Which module?


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## rusty baker (Feb 13, 2009)

Good chance it is the ignition module, but it can't be tested. Might spend $100 on a part it doesn't need. What a ripoff.


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## rusty baker (Feb 13, 2009)

It was the ignition module. At least the wife is happy, she got her car back.


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