Hi all, so I just took the upper intake off my 2004 discovery in order to change the plug wires and I got everything back together after checking the firing order about 20 times and the truck starts and revs up like usual when cold, but after maybe 20 seconds the idle drops back down and then it BARELY stays running...
Also when I apply the gas pedal at this time it blows a LOT of smoke out of the tailpipes.
I believe I have everything hooked back up, with the exception of the breather from the valve cover to the intake... I'm waiting on an oil separator from Atlantic British due here tomorrow.
Could just that one vacuum line be causing all this trouble or should I be looking for something else?
Many thanks in advance for any advice... Of course this happened today in Chicago when it snowed like 6 inches

 

I should note that for the brief time that the truck runs at first it does not misfire and sounds really great. But when the "high idle" kicks off and the RPM's go down it really starts to bog and acts like it wants to die (and eventually does)
I had it running long enough to hook up the scanner and no codes are present.
Definitely acts like a fuel/air issue, I double checked to see if I left any sensors unplugged or anything and nothing seems to be amiss. I did have to remove the throttle cables when the intake came off so was wondering if that is part of the issue? Maybe they are not tightened up so it's not getting enough gas? But seems unlikely as when I try to manually keep it running by fluttering the gas (must be used to old hot rods with carbs ) it has no effect it just bogs down worse. Ok thanks again in advance for any of you wise men who know a million times more than me!!!!!

 

So came back to post an update on this: Sometimes... just once in a great while something has a simple solution. I was just examining everything that had to do with fuel/air last night on the truck to make sure something wasn't disconnected, etc, and I thought I might as well pull the IACV and just have a look. It was completely gunked up and filthy, so I cleaned it out, reinstalled, and to my surprise, the truck ran great after I got it back together. Who would have though. Still not sure what caused it to happen right at that time, maybe it was just being moved around and stuff when I took the intake off?
Anyway, not all good things happen at once, I tried to fill the coolant and bleed the system after I got it running right, and the top broke off of the bleed screw. There just had to be something!