ever since its been a little cold out and i have my new engine, before it is warmed up it stumbles a bit in the lower rpm range. if i am just sitting there with the truck running, i can floor the gas peddle and the engine will stick at 1500-2000rpm. any ideas?

the new engine was just a long block and everything had to be moved over to the long block, the egr vavle is from the old engine could that be it?

 

the check engine light is not on.

new parts during engine change:

plugs
wires
cap
rotor
manifold gaskets
valve cover gaskets
more little small things...