the thing is the new blazer runs but it has a big problem...i was told it was the head...it runs but it is not burning all the fuel...you can smell it coming out the exsaust bad!
also is putting out a bit of smoke...but there are no knocks or ticks in the 4.3 vortech and it seems to drive ok other than being a little sluggish and bogging off the line but once you get into 3rd it seems ok aside from the fumes.

 

also wanted to add ...i just got back from driving it for about an hour...one thing is i noticed that the oil pressure is only about 20psi at idle...and will go up to about 40 when your in the gas...my other 4.3 idles at about 40psi and will bounce back and forth between 40 and 60 when driving...and i was only getting the smoke after coming to a stop for a second then taking off again...the longer i set at an idle the more of a smoke show i get when i pull away...then i got to comparing it to my 4 door 95 and noticed that the ECU BLACK BOX(the one located on top of coolant res) was missing and all the connections that would plug into it are missing also...im working on getting hold of the previous owner to find out whats up with that...i dont know what this controls but i would think it was important....

 

If the smoke has a blueish tint then I'd say it's most likely a head. Is your CE light on? if so run the codes. You COULD have an injection issue with the gas smell - might want to look at those and replace or clean.

 

But if the smoke is black, it's unburnt fuel. And unburnt fuel could be getting into the oil, lowering the oil pressure. Check your oil for a gas odor; if it is there, don't drive the truck until you find and fix the cause.

Pull and check the EGR valve. It might be stuck open by some carbon - clean it real good (especially where the pintle seats) and put it back on with the clean screen gasket.

Pull the upper intake plenum if you do have gas in your oil and check for leaks, which will show up as clean spots.

 

Ok...check engine light is not on....the smoke does have a slight bluish tint to it...And there is deff a strong gas smell in the oil on the dipstick...compared to my other cars and my other blazer it is really strong...

The plan is to take the engine out of my 95 4-door(witch has a bad tranny but runs great)and drop it into my 95 2door and prob gonna turn the 4door into a parts truck or tear the engine down and rebuild the heads...get tranny fixed...and put them both back into the 4 door..because other than the tranny it is a perfect ride...i would just swap the trannys out and keep the 4 door but it is push button 4x4....and the 2 door is mannual lever type on the floor t-case(more reliable right?????

 

Pull the upper intake and check for the clean spots or puddle of fuel like was posted before. Since the fuel is in the oil you probably do have a leak in the plenum. Do a fuel pressure leak down test. That will also so a leak in the fuel system without have to pull the top intake plenum off. If there is a leak it is a very easy fix compared to pulling the engine. Some can do it in a hour and a half on there first time.

 

^ I'll ditto that.

The upper intake gasket is about $12; the fuel pressure regulator should be about $40 if that is what is leaking and, if it is the nut kit (fuel pressure & return lines) it is about $60.

Heck of a lot cheaper and quicker than pulling an engine.

As far as the lever vs. push-button 4x4, I have no idea since I have a Bravada (full-time AWD).

 

sounds like you have a missfire, "seems to drive ok other than being a little sluggish and bogging off the line". your oil pressure is so low due to the gas thining out your engine oil. all of that gas entering the piston is just being forced through the piston rings into the sump and the rest through the exhaust, and before you know it your going to need a new cat. your not getting any spark in that partcular cylinder and should be brung to a shop asap. i forget the exact part that could be causing the problem but im pretty sure its a miss.

 

Well it is fixed! I removed the plenum and checked everything out...there was a lot of gas puddled up in there....one of the injectors in the pass side was completely out!...and another was coming out.....so i sucured everything and put it all back togetther....took it for a spin and it seemed even worse...i brought it back home and tore it apart again....this time i noticed there was still gas puddling in the plenum....i had my wife come out and turn the key over real quick and sure enough there was a feul leak in the line coming into the plenum going to the center distribution selonoid...i replaced the line with rubber fuel hose and replaced everything.....NOW SHE RUNS LIKE A CHAMP!