Motor will not idle down

Question edited for clarity, full make model (what it is)'.

It is a known issue. Check or replace the Unloader valve. Strip and clean the carburetor. Adjust the running speed.

https://www.google.com/search?q=troy+bilt+3000+psi+stalls+when+trigger+is+released

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replace the pressure regulator as it is not bypassing the water when the trigger is released

check for a blocked main jet in the carby
the principle is that when the trigger is released there is no pressure in the pump so the engine is idling
when the trigger is pulled the pressure control valve closes the bypass back to the pump and so the motor is loaded up if there is a problem in the carby ,then the motor will stall

Hi if it stop when the trigger is pulled the issue is with the motor.
stopping is caused by , low revs on motor or low compression or poor spark, sometimes faulty carby.
change spark plug , adjust valve ( when valve has some slight side movment it is ok if up and down , it should be tighter (valves usually under side cover near top ) increase revs a little ( make sure revs dont get rough when running high) set max revs to when the engine still runs smoothly at max.

Yes, full off grease and grease has blocked pressure relief.
needs a big strip down and clean all the grease out. Big job!

almost sounds like the cruise control is engaging

It could be a few things, initially it sounds like simple fuel starvation, remove the fuel filter in the tank and replace, check the fuel hoses, and the primer hoses if fitted for cracks or leakage.

PRESSURE CONTROL WOUND DOWN TOO FAR CAUSING IT TO SPIKE....WHEN YUO RELEASE TRIGGER CAUSING OVER LOAD ON MOTOR WHICH STALLS.BACK OFF THE PRESSURE CONTROL(THE VALVE THE PRESSURE HOSE SCREWS ONTO)IT MAY TAKE AFEW TRIES TO GET IT RIGHT,YOU WILL SEE THE NEEDLE ON GAUGE JUMP RIGHT AROUNDJUST AS YOU RELEASE THE TRIGGER,THAT IS WHEN IT STALLS TURN ADJUSTER 2 MAYBE 3 TURNS ANTICLOCKWISE TO START WITH GO UP OR DOWN FROM THERE WATCH THE NEEDLE ON GAUGE IT SHOULDNT BOUNCE(SPIKE) ON RELEASING TRIGGER

the problem may be the oil. if the oil is fine then try crimping your hose to let less water pressure through. if that still does not work lowes or home depot will fix the problem cheap. thank you for using fixya

common for not starting unless trigger engaged as you are turning the pump as well as engine creating pressure,as for stalling pump has unloader valve which is probably in need of grease(use good silicone grease)this allows water to ciculate when trigger released.