When your Pool Pump isn't Priming, In most cases air is being drawn in, and it could be some of the O-rings in the Jandy valve or possibly the lid.
Priming problems could also due to the CPVC nipple that connects the motor to the filter (threaded on top of the motor) needing to be re-piped. Another possibility is that the impeller could be clogged. Finally, maybe the skimmer basket or pump basket is full or even a clog in the lines could be the cause.