Hello, in most cases with this symptom, the rack pinion gear is bad. there are special valves inside to direct assist left or right. By adding a littl gas, you are building pump pressure and freeing up a sticking valve or so. A pump will not cause loss of assist in one direction. Your rack/pinion is most likely going to need to be replaced. You do however want to put a jack directly under the lower control arm on each side, leave tires on and use your hands to swing the wheel all the way left and then right. just to be sure a strup bearing is not binding. Not likely but worth checking./
The power steering gear includes the following major internal components:
The steering gear rack and piston is supported at the ends in the steering gear housing. The steering gear rack and piston is sealed in order to prevent leakage across the piston. The pinion and valve intersects with the rack and piston and meshes directly with the teeth of the rack and piston.Manual steering is always available during the following situations:
Steering effort is increased when the above conditions exists.The power steering pump provides hydraulic pressure and fluid flow in order to move the gear components. This action occurs when the vehicle is parked or moving. The valve directs pressurized fluid during a steering maneuver. The fluid travels through the external steel cylinder lines in order to act on the rack and piston. When the vehicle is turned right, the steering valve opens and routes pressurized fluid to the left side of the piston. At the same time, the valve allows fluid to escape from the right side of the piston and return to the valve area. The fluid pressure is converted into a mechanical force which is applied to the piston. This difference in force across the piston causes the rack to move to the right. The opposite action occurs when the gear is turned to the left.The effort to steer the vehicle is created by the pressure difference at the piston when the following conditions exist:
Installation Procedure Important: Inlet and outlet hoses must be oriented so as adequate clearance is maintained between both hoses and surrounding components to prevent chafing. Use minimum clearance of 12 mm (0.47 inch) . The outlet hose must not be twisted during installation. Do not bend or distort inlet and outlet hoses to make installation easier. Failure to follow these procedures could result in component damage.