Downstream Not Drawing

So here’s my predicament: I have a Simpson PowerShot 4 GPM 4K psi and the other day I capped off the built in downstream injector because somehow it started back flowing the other day, even though I haven’t used it in forever, and left me with no choice but to cap it. Since then, my injector will not draw with any of my soap nozzles, M5, jrod, etc, it will only flow when I don’t have a nozzle on it. Im running a 2-3 GPM GP high draw injector, and have tried switching my older one with a new unit and the problem still prevailed. I was only running 100’ of hose at the time of my experimentation so that shouldn’t have anything to do with it. I’m thinking that somehow I created too much pressure when I capped off the built in injector, the machine also has an adjustable pressure regulator and I tried turning that down and that didn’t work as well. Has anyone else had a similar issue or have any ideas as to what could solve this issue?

The way around that is to buy a commercial grade machine. It sucks to hear, but it is the truth.

If I recall, you may need to remove the internal venturi inside the built in injector for better flow. It’s been a while since I had such a machine though.

@Innocentbystander Well I’m only doing this as a little supplemental income gig in addition to my full time job and school, so if there was a way to make this one work that’d be about the only justifiable option I have right now. I’d hate to spend another 2-3K when I’m only able to do a few jobs a month. But that would be the simplest solution for sure.

@dcbrock I wonder if I could find a diagram or something that could show me exactly how that sits in there. I removed what I thought was everything I could, just the ball and spring, didn’t seem like there was anything else to take out at the time but that would make a lot of sense (what you said).

Maybe your best bet it to buy a new pump, one that does not have a built in injector. It’s cheaper, and it will be a nice upgrade

@DantheWindowMan Thank you for the suggestion!

@DantheWindowMan @Innocentbystander @dcbrock What would be the best pump to pair with a Honda GX390? I’ve seen where some guys use a Udor 5.0 3500 direct drive with theirs, but the HP formula indicates that that would be excessive for this engine.

You don’t have 4/4k as it is. Put a 5.5 gpm on it. Psi is irrelevant.

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@Innocentbystander Got it, thank you sir!

Hopefully you can find a solution and not have to replace pump…but if you don’t, there are plenty of options out there on the World Wide Web that will work for what you need. Depending on funding, you’d either go back with the direct replacement of what you have (least expensive option), go to another brand of direct drive pump, or decide to go gearbox/belt drive. Check out the power wash store online for pumps if you need to know rough costs for the various options. Your local Northern Tool may have something as well in stock, but their website is filled with more options.

@PPWofLexSC No doubt, unless there is some other component that I can remove that was a part of the built-in injector, it looks like I’m just going to have to upgrade. I’m thinking my current unit is also somehow causing my surface cleaner to leave swirel marks, I’ve tried switching nozzle sizes and the SC is a whisper wash that’s been used maybe a total of 20 hours so I don’t believe it has anything to do with the WW. I go super slow and pre treat yet it still leaves those marks. Anyways, I’m thinking an upgraded pump is about my only option at this point. I’ve been trying to find a 5.5 geardrive and have only been able to find one at this point on Dultmeir, I want to go with an udor or general pump and apparently those with those specs are difficult to find.

Surface cleaner leaving swirl marks could be that you are moving too fast, wrong tips on the bar, clogged tip(s), etc, etc.
You could have a pump that isn’t putting out, but lots of other factors to consider as well - cheaper ones in fact.

@PPWofLexSC I’ve tried different tips and going as slow as possible, and have had to unclog tips in the past. I’m thinking it has something to do with my pump but who knows.

Check your pressure with a gauge. If you feel any pulsing when you spray you may have bad check valves.

If it draws with no tip but doesn’t draw otherwise, that should rule out the DS injector & anything before it as the culprit. I run a direct drive also & it will draw a stout mix even with the engine turned off - using only garden hose pressure. Something creating back pressure like clogged tips or crud built up in your pressure hoses could be the issue. This is how J rod rinse tips prevent soap being drawn in; by creating back pressure. Also, that ‘adjustable pressure regulator’ is your unloader valve & it shouldn’t be used to regulate your pressure. Set it once (properly) & use the correct tips to achieve the pressure you are looking for. I think it sounds like your issue is most likely after the injector.

@TheWizard That would be the best case scenario for sure. The issues did seem to align with the built-in injector failing, and I haven’t used it in years. With my adjustable M5 nozzle there isn’t any room for crud to build up, besides the fact that I don’t hardly use it, I primarily use the xjet nozzle which is the same thing basically I guess just with it’s own injector. Maybe it could be as simple as the filter at the end of the downstream hose? I’ve read that the ball can get stuck and that can cause issues as well. Thank you for your advice, I will continue to run tests to rule out the potential issues you stated.

@Wdwindows It has been pulsating for a while. Especially when the machine is running idle. Maybe that has something to do with my issue?

If you have a filter, take it off

@Innocentbystander Only filter on the rig is the little mesh inlet filter that came with the machine. I’ll take it off and see if that makes a difference.