Hi everyone 

My name is Ricardo, and I'm looking for help

My A3 1.8T 2000 is misfiring on 4th  cylinder so bad.

I have change the spark plugs, ignition coil, swap the injector, and the problem still there on the 4th cylinder.

the engine sputtering all the way even more with the acceleration, the data reader shows only mixture.

any help is very welcome

Thanks

 

 

I suggest you start the diagnosis with a compression test on the engine. It's a simple cheap test that will reveal if there are major mechanical problems with the engine. If cylinder 4 pressure is well below the others you face a very expensive repair.

I would certainly agree with Cliff, since it's simply wasting (already wasted?) money until you ascertain there is adequate and reasonably even, compression on all cylinders. 

Kind regards,

Gareth.