How to check fuel related misfire - 2012 Jetta 2.5

   #1  

CR125Honda

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Getting misfires on cyl 1 and occasionally cyl 2. Vehicle has 155K and I assumed coil pack(s). Yes, I threw money at it instead of a full diagnosis.. Changed all (Bosch), same exact issue.

Oddly enough, it hasn't thrown a code or CEL. I see the misfires happen on VCDS while doing a live test drive.

Haven't tried swapping sparkplugs to see if the misfire follows. Spark Plugs (OEM VW) are relatively new, changed at 125K.

Trying to figure out of it's fuel related, but can not find a fuel pressure measurement anywhere in VCDS.

What is the best way to determine if an injector is dirty or gone bad?

Using latest version VCDS 24.5.0 and HEX-V2

2012 VW Jetta with 2.5L
 
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   #2  

Uwe

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can not find a fuel pressure measurement anywhere in VCDS.
It's old-school, port-injected and runs fixed fuel pressure, without a pressure sensor, so the ECU has no idea.

Check fuel trims.

30,000 miles on plugs? Pull & inspect. Check gaps.

-Uwe-
 

CR125Honda

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It's old-school, port-injected and runs fixed fuel pressure, without a pressure sensor, so the ECU has no idea.

Check fuel trims.

30,000 miles on plugs? Pull & inspect. Check gaps.

-Uwe-
Thank you Uwe,
Will do on the spark plugs. Changed the original set at 125K (which were working fine) but yes it will be smart to check/inspect to rule them out.

I'll report back with the findings.

The misfires are only happening while driving and at low to mid range rpm,
 
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