Did you mark the old HEI housing and cap with a painted line for cylinder 1 at top dead center before taking out the old one. Is the rotor lined up with the mark on the old cap when you installed the new one? If not, you are probably out on timing. I had to change mine last month and it took a few tries to get it inserted properly so the line met up. See YouTube for help in the process of you need it and consult a shop manual for the removal and insertion directions for your engine.