Small Block & Big Block Chevy Specific - new prom, car misses alot when cold! Help!

Ok so i just got a chip for my computer from tpichips and replaced my stock injectors with 24lbs, now when i start my car up itmisses like a mofo @ idle and anything under 1200rpms, but after it warms up it runs like a champ and the throttle response is awsome.
Is this Normal? do you guys think that maybe one of my injector plugs is switched? i emailed Brian @ tpichips but i wanted to ask you guys as well!
thanks in advance!

any thoughts??

Sounds like it is running in open loop the whole time. I don't know how to fix it but we had the reverse problem a car once. I ran great until it warmed up because it was stuck i closed loop. Not sure if this helps just my .02