Code P0304, cylinder four misfire?

Tiny
JACKSON98
  • MEMBER
  • 2013 HYUNDAI ELANTRA
  • 2WD
  • AUTOMATIC
  • 130,000 MILES
Engine code p0304 cylinder 4 misfire changed out both ignition coil and spark plug, and engine will crank but won't start. I even tried the old ignition coil and new spark plug then old spark plug and new ignition coil. I tried 2 different new ignition coils and spark plugs. I even tried "clear flood mode" and pushed the gas pedal while cranking and it almost started but sounded bad and didn't want to mess up my engine. Idk what else to check or what else it would be.
Monday, January 22nd, 2024 AT 2:32 PM

3 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,053 POSTS
Hi,

In most cases, a single-cylinder misfire won't prevent the engine from starting. It won't run properly, by any means, but it should start.

You have already done a lot. Did you check to see if there is spark at the spark plug in cylinder 4? If not, check that.

Here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

Next, if at all possible, record it cranking and upload it for me to hear. It may help me identify a possible issue. Also, when you say it sounded bad, describe what you heard. For example, did you hear something like a knock, tick, backfire, and so on?

Let me know.

Joe
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Monday, January 22nd, 2024 AT 8:39 PM
Tiny
JACKSON98
  • MEMBER
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In this video I have both a new ignition coil and new spark plug in the cylinder 4 spot. I have not checked if it has spark, I will have to check that out but won't be able to for a few days as I won't have time but also what made me think it wouldn't start or at least a factor was the temperature. I haven't started my car for about 4 days, and it's been well below freezing most of those days. Thank you for taking the time to answer me back, I truly appreciate it.
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Tuesday, January 23rd, 2024 AT 2:11 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,053 POSTS
Hi,

It is hard to hear it cranking. If possible, have a helper crank the engine while you record it with the hood open.

I do have a question. When it is cranking, does it sound like it always has? Something sounded off but I just couldn't tell for sure because of the volume.

Let me know what you find as far as spark is concerned. Between the two of us, we'll figure out what is happening.

I look forward to hearing back from you.

Take care,

Joe
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Tuesday, January 23rd, 2024 AT 7:57 PM

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