Scirocco Register

I recently fitted new injectors in my GTX nd now it's running rough, hesitating and rough mainly when accelerating. The seals on the new injectors were very hard so I replaced them with new ones and used red rubber grease.
Any ideas what the problem could be? Thanks

Do the beer bottle injector spray pattern / flow volume / drip leak tests. Even new injectors can be crap

Could be the fuel mixture is now out and running to rich or weak?
Have a look at the spark plugs to see what they look like.