Checking the technical condition and repairing the fuel pump (VAZ-2105)

Insufficient fuel supply to the carburetor may be caused by a faulty fuel pump, as well as clogged or damaged fuel lines. To determine the cause of the malfunction, disconnect the hose from the pump delivery pipe and use the manual priming lever to check whether fuel is supplied. If fuel is not supplied, check the vacuum in the suction pipe. If there is no vacuum, the fuel pump is faulty.

The fuel pump can be tested on a test bench. When the stand roller, having an eccentricity of 1.25±0.02 mm, rotates at a frequency of 2000±40 min⁻¹, the fuel supply should be at least 54 l/h at 20±5°C. The injection pressure at zero fuel supply should be 2.2—3° m H2O.

Wash all parts of the disassembled pump with gasoline and blow with compressed air. Check the elasticity of the diaphragm spring, which should be compressed to 24 mm under a force of 3.2 kgf. Check the integrity of other springs and parts. Cracks and breaks in body parts are not allowed. The suction and discharge pipes must not rotate in their seats or have axial play. The diaphragms must not have tears, peeling or hardening. The diaphragm holes for the tightening screws must not be elongated. Replace damaged parts with new ones.