conv2.3

hi, i have a 93 2.3 mustang w/auto transmission and california emmissions. there is no spark, i changed the crank sensor, coils, timing belt,ignition modual, tried a different brain box, used off ebay, and still no spark! checked the fuse links seems ok, my mechanic says there is power getting to but it is not pulsing like it should. my crank sensor is a bw from advance auto, not ford part and the brain box is from a junk yard said to working but no way of testing.