two simple plumbing questions

allright, first of, kitchen sink
it has a single handle on it to open and mix between hot and cold, all that works

it also has a spray thingy, im sure it is meant for doing dishes, but i like to use it to fill my coffee pot every night, so you can see it is important

anyways, when i grab the handle, instead of diverting ALL the water to the spray nozzle, it seems to divide it between the nozzle and the faucet

so, question one, how do i fix this?

i have allready taken the whole nozzle apart and couldnt find any issues in it

ive been told there is a diverter cartridge in the handle, do i need to replace this?

and this is where question #2 comes in, the little shut off valves in the cabinet i can NOT get them to close
are they made of chinesium or am i just an idiot?


Simple answer. Turn the main off, cut the lines just before the shut of valves under the sink. Replace those, the lines up to the faucet and install a new faucet.

If it's an older set up I'm betting it's full of deposits in critical areas.