yes you need to see whats it pumping ,, my stock pump with vac pump only pumps just over 3psi so i never put a reg in mine but as sayed its only running 3.2lbs from a stock pump ,, that realy could be your prob ,, just get a vac and gas psi gage from autozone ,, you might be pumping 6lbs to the carb n never knew it , that will flud it