When your trouble starts do you get a CEL?
If so, get the code.

What does the white smoke smeel like?

 

Thanks for your link on how to pull the codes...most helpful information I've come across in years! I'll check it out after lunch. Also, I think it will be helpful to make a video of what's going on and post it to YouTube so everyone can see and hear it. I'll link to it here, of course, and maybe we can get a clearer idea.

 

Yeah vids are better than pics!

Better be looking for that leak then. Start checking below your distributor for a leaking intake gasket for coolant coming out. Grab a good flashlight. It would also puddle on the ground below your transmision usually.

 

Checked the codes. Came back with only 12. Normal.
Ran the camera to get the video and after 10 minutes at idle...everything is back to normal. WTF?

Drove it down the road and back and seemed to run just fine until I came to a stop. This seems to be the history of this problem:

1. Runs fine. Turn off. Tune up. Chokes.
2. Replace the new parts one at a time with old parts. No fix.
3. Return all new parts to Blazer. No fix.
4. After sitting all night, runs fine at idle for 1:30. Then chokes and spits white smoke. (Also discovered that engine coolant was nearly a gallon low.)
5. After sitting a while, runs fine at idle for 2-3 mins. Chokes. White smoke is less.
6. After cooling down, runs fine at idle. Turn on A/C for a load. Chokes.
7. After cooled again, runs fine at idle WITH A/C running. Drop in Drive. Chokes.

Now, she acts like she's just fine, except that the idle speed is a little low and needs to be adjusted so it won't shut off in Drive with my foot on the brake. If I power brake and give the motor a little more juice while stopped, it seems normal. A constant and steady, light pressure on the accelerator yields a smooth idle. Would an idle adjustment be all that's needed at this point? And what's your guess at what's caused all this? Could it be the computer was "sick" and it just needed time to fix itself? I love that it's working out on its own, but I hate not knowing why.
Stupid electronics.

Video is now uploading and should be available to link in an hour.

 

YouTube - Blazer (not-so) Tune Up

First video of post tune-up conditions. The first 1:15 recaps this thread. Engine start begins at 1:20.

About midway through the video, you will hear a "squeak" that I thought was coming from the serpentine belt. Now I believe that it's actually coming from the rear passenger side of the motor after getting my ear closer to the block while it's running. Vacuum leak?

Then I got to thinking...remember when I said I used a hammer on the new rotor replacement? Could that banging have caused a gasket back there somewhere to crack or fail? If so, that would explain why this problem showed up between cranks of before and after the tune up. I looked for coolant leaks around the top end. Haven't seen anything yet.

I'm just thinking out loud. Any thoughts?

 

From the info you all have provided me with and from researching other posts, it looks like tomorrow's adventure will lead me to clean/replace the EGR Valve. Will update again once complete.

 

Yea, good idea. Also, just drive it around the block a few times, open her up.

I am pretty sure the plugs are "pre gapped". Call to the parts store and get a part number and verify you got the right plugs. Also, like I have heard many say use OEM parts especially for plugs. Grap a set of OEM plugs, with one gappable prong. You got to think about it like this, and I learned this too, if you have more then one prong on the spark plug only one prong is going to be used all the time unless you break it off. The spark ALWAYS! ALWAYS travels the path of least resiestence. Always! So if you got a Spark Plug with 4 prongs its only going to use the one a fraction of a hair closer to it. Its basically a marketing thing. If ones good mores got to be better? Wrong, but they can sell them that way. Four prongs = 8$ each.

Take back that dist cap and get a different one. I got one where one of the little prongs on the inside of the cap was wiggley. They can't say no.

That valve, (the one in the video) there's no vacuum coming off of it? I have never worked on your type of engine b4, I only got the 2.8L

Check the PCV valve make sure it's open and free. Make sure all vacuum is hooked up.

Worse comes to worse, maybe its fuel pressure. Once you do a tune up it brings everything back to "MFG Specs" Now that the engine can run optimal cause of the new parts maybe your not getting enough fuel pressure.

I would take it for a drive, driving always brings up ideas. Like power when in load when in higher RPM's doesn't seem to be such a problem as a light load.

 

Burning_soul, thank you for that advice...

So, when I got home today, I started by removing the air box so I could get to everything easily. When I laid the whole box on the ground, my eye caught the hole where the O2 sensor plugs in on the underside.

"Oh, crap!" was my thought. I forgot to plug that back in!

So...I put the air intake hose back on and secured it. Then I plugged in the sensor where it belonged, rather that it just flopping around wherever under the hood, and fired her up.

Now she runs as good as she ever has without missing a beat. So, I took her out for a short drive and not once did she stutter. So I guess it always, always, ALWAYS pays to check that you (I) put EVERYTHING where it belongs if you want to keep your baby on the road, and not in the garage!

 

There's no vacuum line coming off it and I couldn't find anything hanging loose back there either. Everything seems to be plugged in and where it belongs.

 

Well its good to hear it was a mistake instead of a lot of money. I hate those sensors, they do a dream in engine management, but when something is wrong or not hooked up right it creates alot of not so easily diagnosable problems.