Frigidaire top spray arms not working, gritty residue on dishes

[Rick52768]

I was thinking about swapping valves and likely will just see if there is any difference but I was just trying to see if I could work on it from a mor scientific approach then trying the part swapping monkey approach. I think before I swap it I will get a baseline on how quick I fill a gallon jug and compare the "new" valve from the donor.

[Rick52768]

Okay, ran the dishwasher with normal setting and it was not bad as I could find only one gritty glass, bowl and fork.  So it sucked!  There is also a fair amount of "dirt" in both sides of the sump.  I checked the water flow coming into the body of the dishwasher and I feel that it is low.  But with nothing to compare it to, I really have no idea what it should look like.  I guess I could take a picture of it filling if anyone thinks that would help?  Would I not see about the same pressure out of the valve as I see in the supply line to the valve? The donor valve has .2-1 bar, 0.021-1 MPa on it's side and my valve has invensys s-101 on it, if this is helpful to anyone willing to answer these questions.  Thanks again for help you can be.

[Rick52768]

Valve flow test: 128oz (gallon) of water in 1:15 minutes.  Total fill time 1:30 with a total of 149 oz.  Sound normal?  Flow from supply side looks like a pressure washer compared to the fill side using either valve I have on hand.  So I would think the house water pressure is not an issue, other than if it drops the fill side would be that much less.

[niobrara]

Rick are you sure your motor pump is just not weak and not moving enough water?

[Rick52768]

No, as I have no idea what a normal acting pump would look like. Looks like good volume of water to me. If I remove the spray arm the water shoots fairly high. Have a good way to test it?

[niobrara]

I set all the arms facing towards the door after it is full and start it. I let it run about 1 minute and slowly open the door and see where the arms are.If there turning, I just fix them I do not design them and sometimes what we bought is what we have. I really dont have any idea what is wrong with that unit it seems to be working as designed. You fill, your have pressure you drain and you have heat.

[Rick52768]

I get where you are coming from.  I am just trying to get any insight into why this dishwasher makes the dish clean, but leaves dirt or grit on them at the same time.  I was hoping that someone who has worked on this crappy model would point me in the right direction, but any brand or model should work fairly close.  The spray arm does turn at a okay pace and shoots water to the top of the tub.  In fact, that is how the grit gets in the bottom of the glasses which are upside down on the top rack.  So the dirty water never seems to be removed from the dishwasher, collects in the sump(s) and sprays on the dishes at even the last cycle.  I would agree with the folks that think it is the volume of water.  Just surprised that no one seem to have a reference on what a normal flow and volume of water should be.  How much water should the tub normally have?  I am sure this may vary make and model wise, but at least an average.

[niobrara]

 Just surprised that no one seem to have a reference on what a normal flow and volume of water should be.  How much water should the tub normally have?  I am sure this may vary make and model wise, but at least an average. OK you need 120 degree water coming in,min water pressure 20  max 120  6.7 gallons per wash cycle .83 flow rate. And it will not work if the water is to hard.

[Rick52768]

What does the .83 flow rate mean and is this 6.7 gallons total wash cycle as in 96 minutes?  The rest I have cover that you stated as I have had a water softener for over a year now. Thanks for the details.

[Rick52768]

Still in need of help or at least that is what the doctors say.  Here is a list of as much information about the recent past:

3-4 factory technicians looked at the problem while it was under warranty with no real change.
Fill time is 1 1/2 minutes
149 oz per fill cycle
Donor valve from the same model (had a couple of leaks) has the same flow rate
House water pressure is 62 psi at hose spigot
Water from bottom of spray arm hits the top of the tub
Back flow valve in place and not deformed
Inlet water temp 130
Water inlet filter clean
Water pressure (flow) to inlet valve strong
Both the soap and jetdry dispensers work
Total run time 30 minutes longer than the chart states
Water can be seen shooting with good force draining into the disposal
The inside of the dishwasher looks brand new due to heavy cleaning (vinegar)
I have forced the sump to be cleaned by forcing it into the drain function and adding water until the sump water is clear.  Dishes on this last run were lighting dirty.
There is always "stuff" floating in both sizes of the sump.  I believe the right side is the dirty "quiet" side and the left side is what water is used for washing dishes.

After a run you can tell that the dishes and glasses have been cleaned (no finger prints, shiny, etc..) but they have multicolored grit (dirt) on them.  So something is allowing the dirty water to mix with the filtered water.  As I am guessing that the two halves of the chamber should not mix and there would be no reason  (water level or lack of, temp of water, etc...) that should change this fact.
 So I feel pretty good and my guess that my problem is due to dirt/grit on the filtered side, but lack the knowledge or work experience to figure out why.  I am going to look at the sump system of my donor unit to see how the two chambers would mix, but still in need of a helping hand to give some pointers in dealing with this portion of dishwashers, Thanks.