WHAT DOES 4AGE 20V BLACKTOP MEAN?

checking out the above photo the acquire off likely straight down on all four ITBs could be the outlet of the tiny gap just by the throttleplate (on my ITBs there's no vacuum there - i.e. worthless)I read through over the internet that when they are not very well synced it can cause rich running, backfiring and vibrations. Maybe I am imagining the