I installed a new injector. A General Pump 100339LG rated to 5-8 gpm. It’s the injector with the interchangeable orifice tips. I have a 3500#/ 5.5gpm pressure pro with a K7 unloader. After installing the injector I have no flow at the gun, it is all going to tank. The injector has .098 etched in it and the specs from the website say the orifice is a 2.3mm. 2.3mm converted to inches is .091 so i’m guessing that’s where that is coming from. Is that orifice too small?
Make sure it’s not on backwards before you do anything else. Arrow pointing with the flow of water. Plenty of folks have put it on backwards and never thought to check that first.
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One of the first things I checked 
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What size nozzles are you using?
My black tip is a 65400 at my white is a 40055
Who set the k7 unloader? It sounds like it might be set way too low.
What happens when you put a high pressure tip in your gun? (Without any injector)
Can you see clear through the injector orifice? No blockage?
The place I bought it from set it at 3400# and if I take the injector off everything works great. High pressure tip or low. And there are no blockages in the injector cause they’re brand new, but I double checked just because who knows what crap may have gotten into them.
Wow. Then I’m stumped.
What orifice was your old injector?
Don’t always assume because it’s brand new it’s in perfect running order, I’ve had many dud injectors Fresh out the packet. You really should carry more than 1 brand new injector at all times, for these particular reasons to actually gauge if it’s the injector at fault.
I would even check that arrow is printed the right way.
I bought two when I got them and I was sure to double check to make sure there was nothing in there
I just went and looked at my old one and it was also a 2.3. I bought two injectors when I made my purchase I’m gonna try the other one. Maybe this one is a dud 
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Going to tank meaning bypass back to buffer tank , or its filling up you chem tank via DS injector poly line ?
going back to the buffer tank
It has to be a dud injector then , I cant think of no other reasoning because your old one at the same size worked.
@mwpws an you remove the orfice inside that injector probably a allen head if you can take it out and run a file across it. Put it back in and test it
So i decided to try the second injector i purchased and everything works! BUT WAIT THERE’S MORE.
After installing the second injector without one of the screw in orifices i decided to put one in and do a draw test. Well when i took the 1/4" hose off the plastic barb broke off the injector so i swapped it from the first injector. Reassembled with a screw in orifice went to do a draw test and now back to square one, no flow to the gun. Now i loosened the injector so to barb point down instead of up and everything works, i get full flow to the gun. BUT WAIT THERE’S MORE, it wont draw anything from my dip tube.
So key point here,
- When barb is pointing up, i get no flow to the gun
- When barb is pointing down, i get flow but it wont draw soap
Is it a rule of thumb to have the barb pointing in one direction?
At this point, go back to using a fixed GP injector.
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I was thinking the same thing. I don’t see the barb pointing up or down making a difference but at least switching to an injector that most of us use will let you know if something else is causing your issue.
