Ignition coil pack

2004 CHEVROLET CLASSIC
121,000 MILES • 2.2L • 4 CYL • 2WD • AUTOMATIC
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DRROCK0074
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  • 3 POSTS
I just re-placed my ignition coil pack and I wanted to know when should I see an improvement in the car.
Jul 31, 2019 at 6:15 PM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Welcome to 2CarPros.

If the coil was bad and it was replaced, you should notice a difference immediately. Can you tell me what is happening? Is there a misfire? Hard start?

Let me know.

Take care,
Joe
Jul 31, 2019 at 8:03 PM
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DRROCK0074
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  • 3 POSTS
Misfires between 1 and 4 cylinders. Hesitation usually when I first start to drive. That comes and goes.
Aug 1, 2019 at 5:43 PM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Welcome back:

When you say coil, are you referring to the ignition coil housing? Also, if you replaced the entire unit, was the ignition control module new?

Take a look at the pictures I attached. First pic I highlighted the ignition coil housing. The second pic, I highlighted the control module.

If you could, let me know the codes you are getting, if this started all at once, and anything you can think of that may help me narrow it down.

Take care,
Joe
Aug 1, 2019 at 7:26 PM
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DRROCK0074
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I replaced the ignition coil pack. The ICM is only a few months old. I tested the ICM and it came up clear. My codes come up P0300 sometimes but they usualy come up P0301 and P0304. Had a camshaft sensor code but I don't have one. It ended up being being the harness for the crankshaft sensor. I replaced that part not too long ago. I did run a test for the throttle sensor. Came back good. The number steadily rose as I opened the throttle. I did clean the IAC and the valve it was in was dirty. After cleaning that the car ran a lot better. Still have occasional hesitation but not as bad. Also had a misfire code but I didn't notice one. Still searching but the car is improving.
Aug 2, 2019 at 9:22 PM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Welcome back:

Have you checked for vacuum leaks? They can also cause a random misfire.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let me know.

Joe
Aug 2, 2019 at 10:30 PM