I went to use my 25 gallon ATV sprayer and had trouble with Shurflo model 2088-443-144 pump. After installing a new pressure switch it still isn't working right. It will pump water for about 5 seconds with hose trigger off, and about 12 seconds with hose spraying water, before the pump shuts off for about a minute. then it will work for 5 or 12 seconds again. then shuts off for a minute. What is wrong with it? Have used the sprayer for spraying brush in fence rows for a couple years. tried changing the pressure shutoff on switch, but no change in pump shutting off.