Outdoor Power Equipment and Small Engines - Pressure Washer help

I have a Generac 2300 psi 2.9 gpm pressure washer.(General pump) When I start it up & start washing it will work fine as long as I do not let up on the trigger. If I let up on the trigger it will not have any pressure after that.(does that make any sense?)I can wash until I run out of gas gas as long as I do not let go of that nozzle trigger.I make sure all air is purged before starting.I would assume since it is not sitting & idling that the pump is not overheating.I have checked my gpm & I am getting close to 6 or 7 gpm from my garden hose (3/4") Any ideas?

The unloader valve is sticking. It needs to be removed and cleaned up.

Is that a DYI kinda project or a take it in to a shop?

Generac power washers had a seal problem in the unloader valve where the pump supplier use a rubber seal that the lip would roll up and stick the unloader valve. This was replaced by two graphite split o rings. A lot depends on the pump on your unit as to whether you can fix it or it needs to go to the shop. Some pump suppliers have unloaders that are very sensative to the minerals in your water and will leave a deposit on the valve stem when not in use. This is why it is very important to try to remove the excess water in the pump when not in use and to use a product like Generac's Pump Saver to lube the workings in the pump and prevent freezing.

Generally the unloader is a DIY job...at least on better power washers. Some of the low end wahsers were so crudely built that sometimes you can't even remove the unloader without tearing it up. Especially when they're stuck in there with calcium and other deposits. You should be able to find the unloader in your manual, or online using your pump numbers, and figure out how to get it out. It's normally easy to get to and fairly simple.