Windshield washer spray works when it wants to?

So, my new to me 08 9-5 is making me want to cry today. So far found 4 vacuum leaks, need to replace the DIC, clean the MAF, replace a wheel hub, front brakes, both Xenon bulbs, both driving lights and I already did oil, plugs and air filter. And I've owned it for 2 days. I've been able to find solutions to the majority of my issues, but this one I can't seem to track down.

My windshield washer likes to work randomly. The headlight ones always work, but the main windscreen washers only come on every 4 or so tries. They are not plugged. And as far as I can tell the pump is coming on, and there are no leaks. I'm assuming this has something to do with a failing washer pump? Any other ideas?

I had a 93 where the washer pump was worn. Acted as you describe.
Noticed a very slight noise change when no water was pushed through. Very slight.
Some percusive maintenance kept it working till I had it replaced.

Thank you, I'll keep an eye on it and replace if it goes out.