Dies when u let clutch out

My truck dies when you let the clutch out, unless you keep the throttle wide open. I can take off but have to keep it wide open. The motor idles low also but its always idled low. I have checked the fuel lines and cleaned them out and checked the fuel filter. I dont know what else to try to do. It ran fine before my son poured about a qt of oil in the tbi. Also checked the charcoal filter.