Had a granite counter and stainless steel sink installed with single unit on/off faucet and a sprayer. Now, intermittently when I lift the faucet, the water shuts off and won't come on unless I jerk the sprayer up and down once or twice. Any suggestions are appreciated.

Sounds like some trash got in your diverter. The diverter's located under the spout, I have put up several types(see images).
Pull the spout and diverter. Now turn on the water to flush out the valve. Replace and test. Good luck, Tom