Help with airbrush not spraying with needle cap off?



Hi All..
Im new to airbrushing just bought a Iwata hp-cs. Have been practicing and wanted to try fine lines when I remove the needle safty cap I get no paint flow except spurts. If I install cap it works Great.

Have no clue why this is happening.

Thanks for any help.

Im not positive that its the needle cap your taking off. You maybe taking the nozzle cap off, or both at the same time and not now it like i did when i started. When you take the nozzle cap off there is no airflow to push the paint until it it balls up on the needle enough for the air to hit it, there for it comes in spurts.
Take a close look and see if the piece your taking off can separate. If you could take a picture of it for us, it will help. Hope this helps.
Hi Seamonkey, my parts book is calling it needle cap? its the small cap at end of brush over the needle in front of nozzle cap.
My guess is that when you take off the needle protector crown, your also loosening the the nozzle cap a little, when it is loose it will move backwards and forwards and this cause spurting, when you put your crown back, both pieces will tighten up at the same time, that's the only possible reason I could imagine why it works fine when its on.
Hi Seamonkey, my parts book is calling it needle cap? its the small cap at end of brush over the needle in front of nozzle cap.

I use the same hp-cs, sometimes mine will stick together when i take the needle cap off. I was just thinking a pic of the cap in your hand would help me determine if this is the problem. Madbrush may be onto something as well, if the nozzle cap isn't sealed properly its allowing the air to swirl under the cap rather than forcing it out the end of the needle.
The only cap you should be removing for finer lines will look like a crown , Hence the name crown cap , Under the crown cap is the nozzle cap witch has a dome shape to it. with out the nozzle cap on the airbrush will on paint stippling effect, A lot of time both the crown cap and nozzle cap will stick together when trying to remove them cause no paint to flow.
Thank you All.. The Crown cap and Nozzle cap were stuck together... Had a bear trying to seperate...Had to soak in hot water and struggle but came free.
Thanks again
Telly 100
Glad my pain and frustration was able to allow me to assist you in solving this problem.
They do say "everything happens for a reason" and this means all my swearing was worth it!!! No you can pay it forward next time someone posts this problem, lol!!!