Help, when I run my dishwasher, it runs through the whole cycle but when I open the door, the soap dispenser door is open but it looks like the soap just runs down the inside of the door and sits on the bottom of the washer. I get some patches of soap that sticks to the dishes on the bottom rack. It seems to work fairly well if I set it to pots and pans but then I’m faced with a 2 1/2 hour wash cycle and all my plastics are shrinking. I thought it was because of cheap soap but even the expensive soap sits at the bottom. What do I need to do?
Here are your parts
http://www.appliancepartspros.com/partsearch/modelsearch.aspx?model=FDBB2040FC1
Here is the tech sheet
http://manuals.frigidaire.com/prodinfo_pdf/Kinston/154526501.pdf
Here is a manual which I thik covers your unit
http://appliancedigest.com/index.php?/files/file/142-frigidaire-dishwasher-24-inch-built-in-electronic-5995293536-service-manual/
You have to join the site to download the manual but it is free and this is a very good site for manuals and other info for the appliance repair DIYer.
Could be a low fill problem most units fill to just under the heating element.
Often if it is a low fill issue, you can hear it, the pump will growl because it is sucking in air.
You can check this by adding a quart or two of hot water after each fill during a cycle. If it now washes OK then I would check the screen filter on the input side of the water valve for a partial plug. If dirty clean it. Do not permanently remove it from the valve as it is there to keep crud out of the valve which could hold it open and cause a flood.
Just be careful to not over fill it.
Also check/clean the filters in the unit and the pump for debris.
I tried to get the Manual and signed up on the sight you gave me but it said I didn’t have access to that particular area 
Try is again as it sounds like you had registration problems.
Sometimes you have to give a site time to register you.