Hesitating on accelerating

2002mazda protege5,2.3 ltr engine.had timing belt changed,then problem started after belt was replaced.took back- scan showed short in #2 cylender
and vacuum code.they fixed coil problem for #2 cylender but vacuum code went away.once rmp get above 2500 accellerates o.k.hesitates when taking off from stop sign,etc.could vac hose be missing somewhere?seems to act like it floods when taking off.does vacuum control timing advance or gas/air mixture?
thanks
terry

Start with the basic maintenance air filter and gas filter and plugs within recommended schedule?

dirty throttle body?
bad throttle position switch?

Vacuum has nothing to with the ignition timing on this car. It’s too modern.

Overactive EGR could cause this. Does it do this when the engine is cold? Like first thing in the moring If not, if it only happens when the engine is warm – and because the EGR is usually disabled when the coolant is below a certain temp – then that symptom would up the ante for a defective EGR.

thanks for tips-it does it with cild engine.once above 2000 rpm or so accellerates o k.if timing belt is off a notch would it cause this?would engine analyzer detect timing off?It was fine until timing belt/master cylendar was replaced.
Thanks!!

If the timing belt was off it will not run very well. Since it worked before the timing belt change and not after, I would say the belt was installed incorrectly. Have them take off the covers and see if the timing marks line up. If not then they screw up.