started to run a little rough got it scanned and said misfire in cylinder two and four
Jan 6, 2017 at 4:20 AM
Misfire in cylinder two and four
1998 AUDI QUATTRO
THEKID24
- MEMBER
- 1 POST
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STEVE W.
- ✓ASE Certified Mechanic
- 15,200 POSTS
Easy tests first. Swap the ignition coils and see if the misfires follow the coils.
If not swap the plugs (or replace them).
Run a compression test to see if it is something internal.
https://www.2carpros.com/articles/how-to-test-engine-compression
If nothing changes and the compression is good then it could be the ignition control module or a couple of bad injectors.
Testing those takes a good scan tool to activate the various parts in sequence and get the results. There are a couple items online about testing the ignition module aka "power output stage" but I have never tried them and they could do damage to a part that is okay.
Misfires are sometimes very tough to track down because of the variety of items that can cause them.
If not swap the plugs (or replace them).
Run a compression test to see if it is something internal.
https://www.2carpros.com/articles/how-to-test-engine-compression
If nothing changes and the compression is good then it could be the ignition control module or a couple of bad injectors.
Testing those takes a good scan tool to activate the various parts in sequence and get the results. There are a couple items online about testing the ignition module aka "power output stage" but I have never tried them and they could do damage to a part that is okay.
Misfires are sometimes very tough to track down because of the variety of items that can cause them.
Jan 6, 2017 at 6:08 AM
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