Low pressure on kitchen faucet - diverter?

I have a nice stainless Price Pfister kitchen faucet set and I'm having issues. I only have 32-35 psi of pressure and I live high on a hill. My kitchen faucet flows very slow, so slow that my wife fills the sink by leaving it run and walks away till its full.

My flow has never been good, the original faucet was installed 5 years ago. It got so bad that visitors commented on how bad it was. I liked the design of the faucet and assumed that there was something wrong with it so I bought a brand new one just like it. Guess what, it's slow too!

Every other faucet in the house is fine but this one. I have already removed the aerator, checked all valves, and replaced the whole thing. I believe that the problem is the diverter valve for the sprayer. Unfortunately there is no way to remove the diverter to confirm, but I'm 99% sure that is the cause.

The diverter on this unit is like a check valve, when the sprayer is used it snaps shut and diverts to the sprayer which does have appropriate pressure. When not in use, water is forced passed the rubber flap which is causing a restriction in the line. There seems to be no way to eliminate this valve which I'm convinced will prove my assumption.

I stopped by a local hardware store and explained my problem, they quickly blamed Price Pfister. What is your thought? Is there a brand out there that would be more suitable given my low pressure situation?

 

I haven't heard of any specific issues with Price Pfister faucets. There are better quality manufacturers out there, but I've found them to be a reasonable quality for their price.

Have you tried running the water directly out of the hot/cold shutoffs (with the hose connected)? This will prove that the flow issue is with the faucet and not the supply.

Comparing this faucet to others in the house, does it just seem to have low pressure, or low flow too? If you filled a gallon pot from this faucet and your bathroom faucet, would one fill faster than the other? Sometimes the faucet aerator can make the pressure appear better by allowing less water through.

(I also updated the title of your post a bit to clarify)

 

I seem to have plenty of flow out of the valves and compared to other faucets, this is the only slow one, even without the aerator. I can fill a 5 gallon water container in just a minute or two in my laundry faucet, that same 5 gallon container in the kitchen would probably take 20 minutes.

The way this diverter is designed, it can't be removed, its a plastic TEE that has a clip that connects to the system. The diverter is a rubber flap/cup with a metal ball in the middle, water has to push between the rubber and the ball to reach the faucet. Opening the sprayer makes the water take the least path of resistance and therefore can't push past the ball.

 

Had that problem on hot side of kitchen faucet. Did blowbacks for several times for a short term correction. Finally removed supply line from faucet and got out a large rust flake that was nearly plugging intake hole on hot side. Reconnected and great flow. It has lasted for around 6 years now.
You might check for something similar.

RR

 

How is the flow when you remove the aerator? Sometimes the slow down is in the screen inside the aerator and needs to be flushed.