since your car is making a popping noise i would think your timing is still out... when you said you rotated the crank 180 back to tdc this was with the belt still on correct?
if so.. cool
now set your engine back to tdc, (take off the cam timing cover so you can align the cam marks) make sure the crank is at 0 and the cam marks are aligned with the backing plate
then follow these instructions for setting your distributor
http://www.cygnusx1.net/supra/library/TSRM...M/ig/IG_17.html