I ran across this in the June 2003 issue in Motor - supposed cure for Idle fluc and an unstable idle - There is a air bypass plug for the thottle plate - 2 plugs are avail - yellow and red
1/8" = yellow
red is for holes smaller than 1/8" -
Check the holes with a drill bit.
Part 12580749 = yellow
Part 12581011 = red

 

nice little tidbit of info. Thanks. BTW, those are GM part #'s.

 

yes Greg those are GM part number - Motor is a good mag to get for underhood "tech" service bullentins etc...
FYI the mag is free
Just give yourself a business name

 

i'm guessing the throttle plate is located near the throttle body..

 

Yea, that's the blade IN the TB.

 

oh.... =X

 

i have a 2002 Sierra w/5.3L it has a 9/64" hole. It has a jagged idle which the dealer says is perfectly normal. I don't get it. Since i am bigger than the 1/8" hole specified i guess it doesn't include me? Any other ideas?

 

So what does this do, change the size of the little hole in the TB plate? Is that the idle hole or something? What will this do, give the engine a little less air? How do you know which one to get and what's to prevent it from falling out and getting sucked intot he engine?
Jim

 

luckdf - according to the SIB - you would need the bigger plug -

 

Y2k - it is a plastic rivet - it plug the hole - stablizing the idle according to the SIB - You put it in pull it thru and snip off the excess - help this helps