Paint gun problem......help!

I have a good quality hvlp top loading paint gun that I am having problems with. It seems that the paint isn't flowing out the tip smoothly. It kind of pulsates out. So as you move the gun side to side it tends to leave vertical bands where the paint was not flowing out. Not getting a constant stream of paint. I always completely dismantle the gun after spraying and thoroughly cleaned it out. I thought that maybe the little filter below the reservoir might not be flowing properly so I completely removed it and sprayed thinner thru it. Still pulsates. The vent on the reservoir can is not plugged either. I can't for the life of me figure out why the paint is pulsating out the gun. The first time I used it I don't remember having this problem. Heeeelp!!

Packing nut

You might try tightening up the packing nut. It should be good & snug, but not so tight that it binds the rod when you squeeze the trigger.

same problem

I had the same problem last week while spraying Stewart Systems primer with my Harbor Freigt HVLP spray gun. Took it all apart and cleaned it real good and it worked just fine after that.

I am having the same problem with my DeVilbiss Finish Line gun. My problem is being caused by a plastic seal being nicked in the spray head. I just got a new rebuild kit that has the seal and all of the wear parts for rebuilding the gun. The part causing my problem is number 4 in the exploded view:

Might need to be cleaned

I was having problems with my paint gun also. I bought a Devilbiss HVLP gun but it started giving me lousy results. I would spray lacquer through it after each use but eventually that didn't work. I talked to a local hanger rat who took my gun apart and cleaned it with a spray gun cleaner called "Naked Gun". It's really caustic stuff (use good quality gloves, not thin latex or nitrile) but it works great. I now clean my gun with it after every use and the gun works great. This is one area that really pays to be anal. I think this stuff will make all spray guns work better whether it's Binks, Devilbiss or Harbor Freight. I bought it at a local commercial paint company.

That part #4 is easy to lose down the drain when cleaning the gun.

And Stewart has a spray gun cleaning product, might not be so nasty to use.

Thanks guys!! I can always count on this forum for help. I'll try several ideas and see what happens. Dan