Unplug the front O2 sensor, and see if it runs any better once warmed up.

 

Just tried your idea. it still did the exact same thing. it ran for about 1 to 2 minutes. it started to backfire so i unplugged the o2 and it didnt recover from backfiring. so that wasnt the culprit. anything else to check for before this thing gets blown up? also "HeyYou" were you able to determine where that vacuum belongs to?

 

Next step is to remove the O2 sensor completely. It'll be loud.... see what happens.

No clue on the vacuum line. Cruise control perhaps?

 

ok so i just took the o2 sensor out. that wasnt the problem so i put that back in. i went out and bought a crank sensor, needless to say problem solved! got other problems now. rear end needs to be replaced, it wont even stay on a hill with it in park. i can hear the gears slipping on the inside so its pretty much shot.

 

Stop driving it. If that lets go at any kind of speed, you will immediately become a passenger with a steering wheel. You will have zero control of where you truck goes. Not a good scene.

 

yea,dont go to far from home if the rear end is going out,i had an old blazer once and lost a pinion gear right in the middle of an intersection!! its not a very good feeling,couldnt push the truck either cause the rear was locked up!

 

im not driving it. its not even registered. I gotta try and find a rear end with 3.90's... it appears to be rare. all i can find are those damn 3.55's!

 

The 3.55s were indeed common.... (understatement...) I think finding a rear with the 3.92s is going to be difficult, at best. Might try chatting with a junkyard that's local to you, and see if they have a parts locator.

If all else fails, try calling Minton Auto Parts, see if they can find one for ya. (shipping is going to be killer though.)

 

Yeah im going to have to be patient because it looks like it may take awhile finding one

 

I have read many threads on the same issues but different descriptions.
I also bought my truck as a work truck. Got it for a good price. Now I am paying for why.
Its doing all the same symptoms as probably hundreds more.
In the last two months since I bought it I have replaced the accelerator position sensor , all 4 O2 sensors. all the plugs. cleaned throttle body. checked air filter,checked cat converter, replaced the fuel pump. I only have electrical and computer left right? It's worse now than it was when I bought it only 2 months ago.
Hesitates, stalls, won't rev past 4000 rpm,
Has anyone figured out what it is?
I have to fix this on my own now or I am going to loose a lot of $$$ in this
On top off not being safe enough to take my daughter in it for fear of it stalling in the wrong place at the wrong time.