What is the difference between the star wheel and the fuel screw?

 

Starwheel is what the spring sits on to adjust the height of the fuel pin. Fuel crew is at the back of the pump to adjust the fuel flow.

 

The star wheel adjusts pre tension on the afc diaphram spring which allows more fuel to come on at low boost levels. Also seeing that you are confused about those two thing i would venture to say this is new to you. With that being said make sure to take your air filter tube off of your turbo and have a piece of plywood big enough to put in front of the turbo to choke the motor out in case of a runaway when adjusting the fuel screw. Make sure to do little adjustments at once and start and check.

 

yeah i knew about the risk of runaway on the fuel screw, that's why im kinda afraid to mess with it. i knew what the fuel screw was because we turned it up on my brother's 92 cummins. i was just confused on the star wheel. thanks for the help!