hesitation only when cold

[GW2]

When i start my car if i let it warm up for 15-20 minutes its fine, but if i only give it say 5 minutes, when i go to accelerate it gives me nothing, then its like all of the acceleration comes at once. i personally think its my ****ty aftermarket maf, but why would it only cause that cold? i plan on upgrading to an lt1 maf soon. need a few more paychecks first.