Chevy 5.3 Intermittent Misfire - Need Help Diagnosing!

Maintenance and Repairs
1

I’m experiencing an intermittent misfire with my Chevy 5.3 engine, and I’m hoping to get some insights from the community on how to troubleshoot this issue. Here are some details:

Symptoms

  • The engine seems to stumble or shake at idle.
  • I feel a noticeable loss of power when accelerating.
  • The check engine light comes on sporadically.

Recent Maintenance

  • I recently replaced the spark plugs and ignition coils, but the problem persists.
  • Fuel filter was changed about 10,000 miles ago.
  • I’ve also run some fuel injector cleaner through the system, thinking it might be a clog.

What I’ve Checked

  • Checked the battery and alternator, both seem fine.
  • No visible leaks or issues with the exhaust system.

Questions

  1. What could be causing this intermittent misfire? Are there particular sensors or components on the Chevy 5.3 I should focus on?
  2. Any common fixes or steps I can take? I’ve seen forum posts about fuel injectors and MAF sensors being issues in other models, but is that the case here?
  3. Should I consider professional diagnostics? I’m okay with DIY fixes, but I don’t want to throw parts at the problem.

Any Input Would be Great!

I appreciate any advice or personal experiences anyone can share. Thanks in advance for helping me troubleshoot this pesky misfire!

2

I’m having a similar issue with my 5.3. The engine shakes a lot when idling and it’s really noticeable when I’m at a stoplight. Anyone else experience this?

3

Yes! My truck shakes too, especially when I’m trying to speed up. It’s like the engine is struggling to keep up. What could be causing this?

4

I had a similar shaking issue. It turned out to be a misfire due to a faulty spark plug. Have you checked that yet, angela63?

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5

Thanks for the tip! I haven’t checked the spark plugs yet, but now I’m definitely going to. Poor acceleration is also driving me crazy.

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6

I faced poor acceleration too! Mine was due to a vacuum leak. Make sure to inspect hoses and connections; sometimes they can be tricky to spot.

7

Interesting, leesarah! I’ve heard that a vacuum leak can mess with the RPMs as well. Does anyone else experience fluctuating RPMs with their misfire?

8

Definitely! My RPMs jump unexpectedly when I’m driving. It’s like my Chevy has a mind of its own sometimes!

9

So many issues can cause this! Have any of you considered checking the fuel injectors? They could be contributing to the misfire too.

10

I haven’t looked into the fuel injectors. Great point! I’m starting to feel like I need a checklist at this point.

11

Sometimes I wonder if it’s just my luck! I mean, how many things can go wrong at once? But we can figure this out together, right? I’m rooting for all of us!

12

Hey everyone! I’m dealing with a Chevy 5.3 misfire. Has anyone experienced this? I’m wondering if it might be the spark plugs causing the issue.

13

Have you checked the ignition coils too? I’ve seen those fail and cause intermittent misfires.

14

I had a similar issue. It could also be fuel delivery problems. A clogged fuel filter can wreak havoc on performance. Have you checked yours?

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15

Good point! Don’t forget about vacuum leaks either. Those can mess with the air-fuel ratio and cause misfires.

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16

I originally thought it might be a simple fix, but diagnosing these issues can be a hassle! Anyone find a surefire test for vacuum leaks?

17

I’ve had luck with using a smoke test for vacuum leaks. It works like magic!

18

Thanks for the tips, everyone! I’m definitely checking the coils and fuel filter next. I appreciate the support!

19

If you’re still having issues after that, it might be worth getting an OBD-II scanner to see if there are any trouble codes. It could save a ton of time!

20

Definitely! Codes can lead you right to the problem. Otherwise, you might be chasing your tail.

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