wierd A4 question

[steven]

Laying A4 up for the winter as usual with raw water cooling intake from a bucket of antifreeze.
Running very smooth when . . . piston#4 (furthest aft) stops firing and just clacks.
Other 3 cylinders run fine without #4 firing.

Anyone encounter this ? Most likely reason and how to firgure out whats wrong? (spark plug wire, coil, blocked fuel jet, . . . )
Tried changing spark plug but that didn't work.

thanks

--Steve

 

[AlaskanPuffin]

The first thing I would do is pull the plug and turn it over and see if it will spark while grounded to the block. If you are getting spark then check the fuel system and intake and exhaust valve function. If no spark then it's probably the coil or plug wire or possible distributor issue. I hope that helps.

 

[steven]

thanks. that helpful. --steve