I have an older 1 HP General Electric water pump that doesn't use a pressure tank and no longer works properly. It draws water from our lake and has worked fine until recently. The problem I'm getting is that the pump appears to be surging (runs at normal speed for a few minutes then slows down then cycles through this scenario for a few times then trips the breaker). I've tried everything I can think of to fix the situation with no success at all. For example I replaced the foot valve, replaced the zone valves, verified and confirmed the start relay box works and has power going in and out, replaced the transformer for the timer controller, swapped out the timer control unit, replaced the fuse and 9v battery on the timer control unit, replaced the capacitor on the pump, inspected the impeller which looks good, took the pump to repair specialists for testing (they said there is nothing wrong with it and that it has lots of power) but it still doesn't work properly. I'm at my wits end. Help please!