I have a Phaser 8500. Sometimes when I go to print something it just prints endless amounts of nonsense code: s8W - !s8W - !s8W - !s8W - !s8W - !s8W - !s8W - !s8W - !s8W - !s8W - !s8W - !s8W - !s8W - !s8W - ! It is very frustrating. The printer tells me I have a bad bouding box. CAn you tell me how to fix this problem? Please.

SOURCE: Phaser 8500 cleaning page

You can't. Just simply stated. It is the way it's designed.
Per Xerox below

NOTE: The automatic printhead cleaning cycle cannot be disabled.
The printer performs automatic printhead cleaning cycles to remove air bubbles or foreign matter that can cause a printhead jet to malfunction. An automatic printhead cleaning cycle is performed when the printer is first powered ON, or if the ink has cooled to the point that a cleaning cycle is required.
Powering OFF the printer longer than 3 or 4 minutes will also cause the printer to perform a printhead cleaning cycle when the printer is powered back ON, which uses ink. To minimize ink consumption, keep the printer powered ON at all times.

SOURCE: Phaser 8500 print problem

There is an encoder on the end of the drum and some of the lubricant from the maintenance kit seeps into.
That encoder will need to be cleaned well or replaced.

SOURCE: How to turn off the cleaning page feature in Xerox Phaser 8500

Actually what is happening is your machine is going into the power save mode and staying there for a long time.
What happens then is you get a full warmup. When the machine warms up, it will turn on the compressor and drain the resivour because Xerox wants a "fresh": supply of ink in the print head.
Its excruciatingly expensive and wasteful.
Here is something that can help. I am not sure you can completely disable the energy save mode. Thanks Al Gore...
NOTE: To save energy, the printer enters a power saver, low-energy consumption mode after a predefined period of time since its last activity. In this mode, most printer electrical systems are shut down. When a print job is sent to the printer, the printer enters the Warm-up Mode. You can also warm up the printer by pressing the [OK] button on the Control Panel.
If the printer is going into Power Saver mode too often and you do not want to wait while the printer warms up, increase the length of time before the printer goes into the Power Saver mode.
Modify the timeout value:

1. Press the [Up] or [Down] arrow button on the Control Panel to select [Printer Setup] on the Display Screen, and then press the [OK] button.
2. Press the [Up] or [Down] arrow button to select [Printer Controls], and then press the [OK] button.
3. Press the [Up] or [Down] arrow button to select [Power Saver Timeout], and then press the [OK] button.
4. Press the [Up] or [Down] arrow button to select the required timeout value (30 - 240 minutes), and then press the [OK] button.
   
   NOTE: Select a larger timeout value to extend the length of time before the printer goes into the Power Saver mode.
   
   
5. Press the [Up] or [Down] arrow button to select [Exit], and then press the [OK] button to return to the Main screen

SOURCE: Phaser 8400/8500/8560 maintenance kit

No, it will not work because the chip (CRUM) is not compatable.

SOURCE: Xerox Phaser 8500 Pause

Go into Control panel, Open the Printers/View installed printers.

Right click on your printer, and remove the "Pause Printing" check mark.