Intermittent spark

Replaced the cap and rotor. Still not firing up. Pulled the distributor out (with the cap removed this time) and spun the shaft to see if the coil wire would spark against the intake manifold. It sparks great when it spins fast but at low speeds like when the engine is trying to start, it has no spark whatsoever. I guess it’s the distributor pick up?
I figured it was the pick-up when you said it fires while the distributor not being bolted in. This is and easy test when diagnosing no spark. Plug another distributor in and spin it. If you get spark your pick-up is usually the problem