1988 dodge ram van with 318 the im having is problem it seems like it starving for gas but everything is good and when sitting the engine runs ruff?

Injection or carburetor?

Injection:very common to have one of the injectors become partially plugged and deliver a poor mixture making run poorly on four cylinders. Carburetor:The interior passages of the carburetor could be plugged Both:These symptoms are most commonly caused by ignition wires, spark plugs, distributor caps and rotors.