When people refer to timing an autococker, they are talking about the process of setting up a 'cocker so it shoots properly.
Crash Course in Cockers:
When the trigger is pulled, there are two stages to the firing cycle - the actual shooting the paintball and the re-cocking (reloading) the marker.
When you pull the trigger, the sear is released in the first part of the trigger pull, sending the hammer forwards which releases the gas from the valve.
As the trigger continues to move backwards, the 3-way (or 4way or 5 way - all the same thing) is switched, which reverses the gas pressure inside the ram - this then pushes the back-block and bolt back - allowing a paintball to drop into the breach. Releasing the trigger switches the 3-way back, reversing the pressure on the ram, closing the breach.
The art of timing a cocker involves getting the two actions correct in the trigger pull - if the sear is released too late, or the 3-way switches too early, things don't go to plan, and you end up with paint soup.
Having re-read that, it all sounds complicated, but it really isn't - the key thing to remember about cockers is, "if it aint broke, don't even think about fixing it".