Well, I got it changed out. Took me about 4 hours (I was going slow) but it fired right up after I got everything buttoned up. Now onto the next problem- it runs like poo. I think there is a bad vacuum leak because when its running, it barely idles, runs rough and shakes like crazy. It smooths out if you give it some gas. It seriously feels like its running on 3 cylinders. Here is my list of item to change/fix/check:

Full tune up - plugs, wires, distro cap and rotor, oil change
Clean the IAC and EGR
Replace coolant temp sensor and oil pressure sensor
Change fuel filter
Replace radiator - leak somewhere and possible trans cooler leak (red "mud" everywhere inside)

I can't really complain though; I bought if for $350 from a buddy. So far I have this invested in it:

New fuel pump and hanger assy (Delphi) - $155
Fuel filter, coolant temp sensor, oil pressure sensor - ~$50
2 used rear tires - $100

The only problem is I'm short on time... I deploy for 6 months in August. Oh well, I'll just have to jump back into it when I get back...

 

Might wanna check for fuel pressure bleed off and investigate that fuel injector for leaking... Its only the most common runability problem around here with these older engines. It would appear the injection spiders are only good for about 15 years Theres a plethora of info in this forum on it man have a read. Its an easy fix to do at home.

 

When you did the tune up did you use ac delco parts . these trucks hate any other kind of parts and the engines wouldn't run right

 

^^^ nuh uh. They like Ngk plugs too! Just no bosch or autolite plugs. I dont know about champions in the blazers. Ive never run em in em.

 

I forgot to mention its a TBI 4.3... I haven't bought any of the tune up parts yet but I will try to get AC Delco parts when I do...

I'm hoping it isn't something major (blown head gasket or something) and that a good tune up/fluid flush will make it drivable.

I also forgot that it smokes a bit when running. Not a whole bunch but enough blue smoke to be noticeable. Again, the truck sat for 6 months. I was told it ran before sitting but that's a very broad statement LOL.

Is there anything else I should look out for?