First make sure your flow control is set to open then open your solenoid just so it is hand tight like an oil filter. More often than not they get torqued down way to tight and cause a vacuum on the diaphragm from opening all the way. Lastly if that does not work remove the solenoid and manually bleed the valve and break the vacuum between the solenoid and diaphragm by removing it and letting water to flow out the 32"inch hole in valve. That should take care of your problem of flow. Not a voltag...
