Why is your 1993 Chevrolet cheyenne not starting?

Check all vacuum lines and make sure they are both undamaged and hooked up correctly, as well as the vacuum itself. If the vacuum system is fine, try spraying the inside of the throttle body with carb and choke cleaner. To do this, remove the 2 wing nuts on the air filter housing and take it off of the throttle body. This will reveal the twin injectors and butterfly valves. Spray the carb and choke cleaner moderatly over every surface and try starting it. If it still wont start, the problem may lie with the starter, battery, electrical wiring etc, etc.