Ignition coil

STINKY36

MEMBER
1991 BUICK PARK AVENUE
0.8L
V8
4WD
AUTOMATIC
165,000 MILES

Well, my car kept shutting off on me. Took it a shop he said the wiring harness. Well he fixes that and it ran good for I'll say about a month month-and-a-half. The problem has returned only this time it's now backfiring. I take it to a different shop they put it on the OBD and it did not read any codes. They said wiring harness again and it was so hot that it was melting the plastic around the wiring harness. So I take it back to the man that did it he saying ignition coil could that be so or is it the wiring. He said when it starts it sends off sparks, but I've never seen it do that when trying to start it.

5 Replies

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi and thanks for using 2CarPros.

If the coil is bad and arcing, yes that can cause the drivability issue. However, that isn't going to cause the wiring harness to melt. If you still have the car, when it is dark outside, open the hood and start the engine. Inspect the coil to see if you see sparking.

Keep in mind, a bad spark plug wire can cause an arc and it may not even be the coil pack. Additionally, these ignition coils are mounted on an ignition module which can also go bad, causing a misfire.

One last thing. I have no idea which harness was replaced or what appears to be melting. I will tell you that if something is arcing, it will produce a lot of heat.

I attached a picture of the coil for you to see. It is located on at the end of the right hand side at the end of the valve cover.

Let me know if this helps or if you have other questions.

Take care,
Joe

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Friday, February 8th, 2019 AT 8:09 PM

STINKY36

MEMBER
3 POSTS

Okay, thank you so much, and yes this has helped me a lot. I do still have the car and when it is warmer out at night I will check it out and let u know what happened. If I end up needing a ignition coil exactingly which one do I need?

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Friday, February 8th, 2019 AT 9:08 PM

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Welcome back:

The coil needing replaced will be based on where you see the arc. However, don't just arbitrarily replace the coil until you confirm it isn't a bad spark plug wire. Where you see an arc, make sure the engine is off, and inspect the plug wire. If you see a gray spot on the plug wire where the arc occurs, replace the wire. I can help you at that point.

Let me know what you find or if you have other questions.

Take care,
Joe

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Friday, February 8th, 2019 AT 9:54 PM

STINKY36

MEMBER
3 POSTS

Just got brand new module the black piece and the silver piece has been replaced along with all the wires. So I know for sure it's not the spark plugs. I've also bought and replace a mass air flow sensor a crank sensor a few other parts, but they wouldn't have anything to do with why it keeps stalling out. Oh yeah, and the wiring harness was on the passenger side of the car in the corner close to the windshield.

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Friday, February 8th, 2019 AT 10:01 PM

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi:
Not the spark plugs, but rather the spark plug wires. That is where an arc can happen. Even if the plug wires are new, something may have happened to one of them.