I do not always have pressure. Water will com e out and when I do have pressure as long as I do not release the trigger it will continue to have pressure. When I let off the trigger and the press it again it will take several tries to start again.

You have a leaky seal it needs to be changed

If you are unable to shut off the pressure from the wand, there may be an issue with the unloader valve that is stopping it from switching into bypass mode when the trigger wand is released. The unloader valve is designed to respond to the spike in pressure created when the trigger wand is released, and to divert the flow of water coming from the pump to bypass the pressure hose and flow back into the intake end of the pump. If the unloader valve fails to switch into bypass mode, water may continue to flow out of the trigger wand. This may also cause damage to the wand. If you are unable to shut off the pressure from your power washer, stop the engine and discontinue use immediately. The unloader valve should be removed and possibly replaced if found to be malfunctioning. The inability to stop the flow of high-pressure water from the wand can be dangerous and should be fixed before continuing to use the machine.

Hi Cliff:
My experience is that the pump pressures prevent the engine from starting, so we hold the trigger while starting.
My brother has cut a wedge of wood that he uses to jam the trigger open to bypass the problem. It can get a bit wild if the wand is not secured when the unit is started..

Hi there! To prepare for cleaning, put the solution and water in the top tank. While cleaning, all the dirty water gets sucked into the bottom tank. To clean squeeze trigger to release cleaning solution and slowly push carpet cleaner forward, this equals one wet stroke. Continue to squeeze trigger and slowly pull carpet cleaner back toward you (second wet stroke). Release trigger and slowly push carpet cleaner forward over area just sprayed with solution (dry stroke). Then slowly pull carpet cleaner back toward you without squeezing trigger (dry stroke). To avoid saturating the carpet don't do more than 4 wet strokes over one area. Always end with dry strokes. Here is a link to view the instruction manual if needed.
http://hoover.com/file/604/

Hope this was helpful!

If the washer is the kind that shuts off completely when the pistol grip is released, the problem is likely the little pressure sensor located near the output fitting (the threaded part to which the hose connects). The sensor is a little plunger held down against an opening in the side of the pipe by a spring when there is low or no pressure in the output pipe, as when the trigger is pulled and the pressurized water in the hose is released by pulling the trigger. That completes the electrical circuit and the washer is on and continues pumping water. When the trigger is released, water in the hose and output pipe jams up super high pressure, forcing tjhe little plunger out against the spring, and the electrical circuit is broken. If you take the case apart, you will see wires coming from that area. The fix (if this is the problem) is to free up the little plunger.

It is probably air locked....Here's what you need to do. Connect the garden hose, and HP hose, but not the gun. Turn on the water, and let it run while you make sure that there are no high points in the garden hose that can trap air....Work the hose so that any air is displaced through the pressure washer. Continue in this manner through the HP hose. Shut off the water and connect the gun. Turn the hose back on, and operate the gun for several minutes, pulling the trigger and releasing. This alternately allows the water pressure to build up on house pressure and then to depressure, pulling residual air from the system. Release the trigger, and start the machine. Usually, this is enough to get full washing pressure. If it is very difficult to start, you can hold the trigger down on the gun and pull the start cord at the same time. Holding the trigger down acts as an unloader, making the starting easier.
Hope that this helps, --W/D-- please feel free to rate this solution! Thanx!

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

Dear allbusiness9,
This problem is most probably due to a faulty Spill Valve( also called Control Valve). When the gun is released the spill valve is compressed and it either closes a micro switch or just opens from the bottom and keeps the water circulating. All spill valves keep the water circulating from the bottom part. Now when the gun is pulled (opened)...the spill valve extends and closes the bottom part, and thus water goes out of the nozzel. When you work with no nozzel, there is enough water flow to close the bottom part of the spill valve. So when the nozzel is placed back there is no chance that the bottom part leaks water. When the gun is started with the nozzel....the bottom part of a FAULTY spill valve,..will colapse and pressure drops. So to fix the fault you must change the Spill Valve. In some occasions, I also found that suction valves give this problem. A faulty sucktion valve will colapse under high pressure, and lets water pass the other way round.
But in my opinion and experience, your problem is in the Spill Valve.
Regards,
Fulltech.

When you press the trigger an angled piece on the end of the plastic rod attached to the trigger pushes valve button in that then releases fluid. On releasing the trigger, the valve button is supposed to be pushed back out by an internal spring. The button gets sticky with evaporated cleaning fluid and does not come back out, causing fluid to continuously run. Try taking the machine outside, fill the tank with very hot water, pull the trigger, and let the clean, hot water flow through the valve. Perhaps it will free up. If not, the valvle will have to be replace. Either way, once it is working, ALWAYS flush the entire system with hot, clean, clear water to remove any cleaning solution in the system or it will only clog again