Test Point 7 - Fuel Pressure
TEST POINT 7Fuel Pressure
1. Open flap on distribution tube. Unscrew capped nut on test connection.
Note: Be careful that sealing ball does not fall out when removing the capped nut.
Catch escaping fuel.
Electric sparks could cause fire!
2. Connect pressure tester P 378 on distribution tube.
3. Start engine and measure fuel pressure at idle speed.
Specification: approx. 2.0 bar (29 psi).
4. Pull off vacuum hose on pressure regulator. Fuel pressure should rise.
Specification: 2.3 to 2.7 bar (33 to 39 psi).
5. If fuel pressure deviates from specified values, pinch return line shut slowly with a clamp.
Replace pressure regulator if pressure rises above 4 bar (58 psi).
If pressure remains below 4 bar (58 psi), check fuel filter or replace fuel pump
If engine does not run, supply battery voltage to term. 4 of 9-pin plug or bridge terminals 30 and 87 b on socket of fuel pump relay.
Fuel pump should run.
Specification: 2.3 to 2.7 bar (33 to 39 psi).
Tightening torque for capped nut: 22 Nm (16 ft lb).