If you have the correct tools ahead of time (it's a star type tool, not sure of the name or the exact size) and everything is warm and flexible, it's not hard to do. (don't like to spend others money, so decide if you want to spend a bunch on a set of socket end star bits, screwdriver type, or a folding multi size tool). If you're less than six feet tall, you'll probably want to be standing on something sturdy, or you'll be balancing on the fender and reaching.

If you are 5'8" live in an area that stays below 30F and the blazer hasn't started in a while, then it's a challenge.

Problems I had were, cold - everything is stiff and difficult to move to get light and tools in place. Not having a long star type screwdriver or setup that could use a ratchet with extension, getting light to the area because of daylight, dropping screws, dropping O-ring and everything being too stiff to move to get at everything.

They do make sensor cleaner that works great on the IAC valve and you may be able to get the correct star size by asking at an auto parts store.

 

Hey -
thanks for this thread which I just discovered, das96blazer!

I seem to have the same or a similar problem.
There is a dramatic plume of white smoke coming out of the 4.3L engine of my 91 S10 Blazer when I start it up after the car has been parked for a while (e.g. 2h).
It is so bad that I usually wait for a moment until nobody is around before I start up my engine.
Just so you know... I live in San Diego and there is no reason for anything to condensate on normal days

It used to be only the first 3-4 seconds the engine runs, but now it keeps on lingering a bit longer. After a while though it stops completely.

Suspecting it would be the head gasket I finally did a compression test today.
I removed all the spark plugs and they all looked perfectly fine, not discolored or "washed" at all. There was not sense of "moisture" from any of the cylinders.
The compression test also came out fine, 150-155psi uniformly on all cylinders reaching the maximum after ~3-4 strokes. I was expecting a more dramatic result to match the dramatic fog effect for sure.

This thread gives me some hope that it may be something else than the head gasket, something that is easier to fix myself maybe?

I will also check through the various valves and components you mention, awe341.

Long story short... I'm very curious if you got your smoke problem under control and whether it ended up being something outside of the valve/heads/cylinders/rings/etc. area.