After my cam install i have a little surging and rough starts, so i planned on enlarging the hole and adjusting the idle screw. I heard 15/64-17/64 was a good size so i got a 15/64 drill bit and a T15 torx. I started by turning the idle screw about a quarter turn, when i took the induction hose off the TB i realized the hole was already bigger than 15/64, approx. 1/4" maybe more!(no it has never been touched)

The idle adjustment helped out alot so i don't think i will have to drill the hole bigger?

I also noticed some oil behind the blade, so it looks like i will be doing the PCV mod.

 

I belive its a bit smaller than 13/64.. that was
my first size now its 15/64.. I then added a
.022" spacer on top of the idle screw. I did not
want to adjust it in fear that I could not get
it back to factory setting. Car is great now.
This summer with ac on with tell the real storie.

 

TA_2001; thanks for the reply. Is it possible that my 1998 has a larger hole because of the larger injectors? Has anyone measured the hole in thier '98?