Multiple cylinder misfire, electrical problem?


Passed Driver's Ed
Grand Cayman
2008 3DR Golf GTI
Hey everyone, so my MK5 GTI is in the shop right now. I had a leaky injector on cylinder 3, one day the car broke down on me and was misfiring terribly where before it was an occasional misfire. I had the car taken to the shop and the injectors have been replaced along with a carbon cleaning and new coils and spark plugs.

All parts used are OEM and plugs are NGK Iridiums which I have used in the past with no problem. However the vehicle is still showing misfires on cylinder 1,3,4. The shop suspects an electrical issue and they are intending to go through wiring for injectors and coils.

They have checked compression and tried different plugs and coils but with the same result.

Unfortunately they are a busy shop and are taking a break on my car to work on others too so I’m asking in the hopes anyone else might have any idea or have had similar issues. It’s been over a week and I would just like to get my car back on the road!