I have a dakota 2.5 liter that is running very rough, it sounds like it is misfiring, I replaced the distributor and rotor, it is better but is still popping. Any advice would be very helpful.

Used a timing light and got weak signal from fisrt wire, hooked it up to the second and it flashed like it should, I then switched wires from the second and put it on the first and got the same outcome, like earlier stated I replaced the rotor and dist. cap ( not the entire dist.) could the problem be with a faulty dist.
Thank you
Will