I bought my buddies '95 Blazer. It fires up fine and drives fine but idles very rough and stalls at stop signs and lights.
I read a lot on this forum about EGRs getting clogged and such so decided to take apart a few items to see whats going on.
I disconnected the platic intake pipes and filter box and removed them.
The EGR is kind of a pain to get to so I decided to pop off the top and see whats inside.
I took off the cast intake manifold/throttle body, this is what I found:

Lots of oily dirty residue and a crustyness. I would like to clean it all out as much as possible safely. I don't want to cause any internal damage to valves or something if crusty gets inside..
Questions (color coded to the arrows in the picture for ease of explaination):
1) What would be the easiest way to clean the basin areas?
2) Should I shoot carb cleaner down these tubes to clean them or use a rag or something? I assume they are intake chambers of some sort.
3) This yellow port has a crusty buildup that I assume made its way to the EGR because a small chunk of the same material jammed the EGRs piston open, which I hope it the easily fixable cause of the rough idle.
If I start chipping away at this crust where will it go, out the EGR intake port in the front of manifold or into the engine? What would be a safe way to clean this crust out (which I beleive is the main culprit)

I'm currently cleaning all the sensors with carb cleaner and plan to clean the inside of the removed top portion of the Intake Manifold/Throttle Body with degreaser and carb cleaner. Maybe hit it with some paint while its off also.

One of the EGRs bolts was missing and someone decided to replace it with a bolt that was too big and broke the threaded part off. Theres enough to get a bolt and nut on to tighten it up but I will also use some black RTV sealant.

ANY advice or tips are greatly appreciated, thanks in advance!

 

Red and blue would be easily cleaned with a rag and carb cleaner, yellow you could hold a shop vac over the hole while cleaning it with a screwdriver, the shop vac would keep the pieces from falling in.

 

Judging from the pics and from how clean the right (passenger) side is you may have the infamous leaking fuel pressure regulator.

Also be careful with the RTV at the EGR valve. It could clog it up too.

 

Love pictures! Volfan called it. You need to change the FPR It is shot. The entire inside of that thing should look crappy. The clean area is from gas washing from the FPR. Make sure the parts guy gives EGR gasket upgrade with the screen on it. If they don't have it go someplace that does. Trust me I have the same one and was taking it apart every three weeks till I got the gasket with the screen.

 

Had the same idea about using the shop vac, so good to go there.

Going to be frugal with the RTV also, I know that stuff can easily get into places you would rather it not!

The Autozone (Duralast I think) EGR has a screen built into the gasket so good to go on that also.

Had no idea about the pressure regulator thing so thanks for the heads up on that. I wondered why one side was cleaner than the other. From what I read up on here about it the failure of the FPR led to the engine running rich which may have been the cause of the excess build-up of carbon which in turn clogged up the EGR and both conditions are giving me a rough idle and stalling out...whew! So going to get that replaced, clean everything up and re-installed, and cross my fingers!

Thanks for the great responses guys, helped me out a bunch. Going to knock all that out this weekend and post an update about how it went.

 

Well I cleaned all the sensors with carb cleaner, replaced the EGR, FPR, and plenum gasket...so far so good. She seems to be purring like a kitten now.