hey all, new here...

I have a 2001 5.9 Sport 4x4 1/2 ton and i recently replaced some cracked heads. I put everything back together, made sure there were no vacuum leaks, etc., but when I start it up it runs rough and is kinda noisy....

Now, when I had the rocker arms off, i turned the crankshaft clockwise to where the v8 symbol lined up with TDC to set it to a neutral position, but I overshot it by about a half inch and cranked counterclockwise to set it back...

Could this be my problem?

When it runs it idles at about 1000 rpm and when I accelerate it kind of steps down when i let off.... it'll drop a bit at first, then hang, then it'll drop down to around 800 and the engine is noisy.

just wondering what the hell is going on.

 

drove it around the block a few times and had smoke come into the cab through the a/c vents... help... please?

 

Did you do anything about the plenum gasket while you had the intake off?

Did you remove the distributor, or move it at all?

Didn't pinch any wires back there did ya?

Got your firing order correct? Wires routed per TSB? (can find that one in the faq section.)

 

didn't touch the distributor at all. i know i have all my plugs where they need to be. The engine isn't running rough so much as its that terrible sound the engine is making like it's low on oil, but i've got 5qts in it.

didn't do anything about the plenum and i'm wondering if that could be it. Hell, i didn't even know there were problems with it until i came here and started reading some of the posts.

also wondering if maybe the valves are hitting the cylinder? don't know what noises mean what. Pretty new to this whole thing.

I spent a couple years at a CAT dealer in the Heavy Rentals department as a parts changer, so i know my way around an engine, but that doesn't make me a mechanic.

 

all sorts of noises come from a bad vacuum leak. check ur lines. make sure all the vaccums from the plenum are on there good. Otherwise you'll experience what's happening right now...

 

if you havent messed with the plenum, that be should 1st on your list. that thing causes all kinds of weird problems. it's fairly easy to do. with the right tools you could have it done in a day or 2.
when you do that, check all your other vaccum hoses. like the other guy said, vaccum leak will cause some pretty weird problems.

 

I think all the lines are good, secure fits. There's a plastic line going into the front of the throttle body that could have a crack in it I can't see because of the sheath covering it. Ill replace it to make sure. Thanks for your help guys.

Something in the back of my mind is telling me there's something off with the fuel injection... but, I guess it could be anything simple at this point.

Ah, the learning process...

 

if you didnt mess with the distributor, it shouldnt be off. if it is, it shouldnt be off enough to make a huge difference. i think the tollerence for "in range" fuel sync is +/- 4 degress. it might be less. but it shouldnt be off that much unless you messed the dist. in some way.

if you can get your hands on a high end scanner like an OTC genisys or something like it, you can check it and correct it fairly easily, if its off.

 

Double check to make sure your wires are right, it only takes one to make it run weirdly, but it will still run.

 

espescialy the ground(s) by the back of the head. there may be a pinched or missed a ground wire.