MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: xcb789 on July 16, 2025, 02:04:57 pm

Title: Cylinder 1 Misfire,
Post by: xcb789 on July 16, 2025, 02:04:57 pm

Hi all,
I have a misfire problem under load from cylinder one, Idles fine albeit not perfectly smooth but when it comes onto boost or try for high throttle it stumbles and the engine light flashes. Swapped coils and plugs and still cylinder 1. Ran some injector cleaner through it and it does seem to idle a bit smoother but still getting misfires. If you ask only 30 ish percent throttle then it will climb the rev range okay. It is when asking a lot of it that it goes. Floor it and it just stumbles at any revs. Is injector looking most likely? I understand these engines get carbon build up but that would cause different behavior wouldn't it?
Thanks for any replies.

Title: Re: Cylinder 1 Misfire,
Post by: ZoliWorks on July 17, 2025, 04:05:39 pm

Same symptoms as you, was a faulty injector. It was a brand new S3 injector from the dealer as well. Failed after a month.