TNVD SRZ (fuel filter check)
Check fuel filter compliance (RENAULT filter with matching part number).
Check the position and degree of contamination of the filter element.
Check the installation and condition of the gaskets.
If there is metal shavings in the filter: change the fuel filter, bleed the systems and continue the diagnosis.
Checking the fuel supply to the injection system from an external fuel tank
The purpose of this operation is to detect a possible malfunction of the low pressure fuel supply circuit, completely replacing it with an external tank.
Order of execution
Disconnect the supply hose from the fuel filter inlet and close the hose opening with a plug.
On vehicles with electric (not manual) priming pump, remove the pump power relay.
Connect the hose to the fuel filter inlet and dip the other end of the hose into a clean container with a capacity of about 5 liters.
Disconnect the fuel drain line from the fuel temperature sensor (draining fuel from injection pump and injectors) and plug the hose opening.
Attach a transparent hose to the fuel temperature sensor fitting and lower the other end of the hose into a vessel.
Fill the container with clean fuel.
Start the engine and wait until the air is removed from the system (there must be no air bubbles in the drain hose).
Fault resolved
The low pressure branch is fine. Reconnect the disconnected low and high pressure fuel lines and run the troubleshooting algorithm or DTC that requires this test.
Low pressure branch connections incorrect and defective
Make the necessary repairs.
Low pressure branch connections are correct and correct
Check the condition and operation of the manual or electric fuel pump (depending on engine model). Troubleshoot if necessary and continue testing.
If the malfunction occurs when the fuel level in the tank is low, check the correspondence between the actual fuel level and the instrument panel readings.
The fuel intake unit sucks in fuel through the Venturi tube located in its lower part. Check if the venturi hole is clogged (diameter 6-8 mm) dirt accumulated in the tank. Check the filling of the low pressure circuit of the supply system with fuel.
Check the quality of the fuel you are using.
To do this, compare the fuel with a known clean one: gasoline, solvents, diluents, sulfuric acid (giving the fuel a whitish appearance), water or oil.
If the fuel is contaminated: change it.
Replace fuel filter.
Bleed air from the high and low pressure circuits of the fuel system.
Features of the low pressure circuit of engines equipped with a fuel priming pump
This pump only works for a few seconds when turned on «ignition» and starting the engine.
Check if the pump delivers fuel in the indicated phases of operation. Make the necessary repairs.
HPFP SR1 (fuel filter check)
Join (through the tee) pressure gauge with measurement limits of 0-5 bar to the injection pump inlet and read the pressure gauge readings with the engine running.
If the pressure is less than 1.5 bar, connect a pressure gauge to the filter inlet and repeat the operation. If the pressure has not changed after this, disconnect the hose from the filter inlet. Substitute a container for drained fuel. Check the fuel supply when the ignition is switched on. If the fuel supply is approximately 1 liter in 30 s. booster pump and fuel lines to the pump are in order.
Otherwise, replace the fuel filter head.
If the pressure is between 1.5-2 bar, the low pressure circuit is OK.
If the pressure exceeds 1.5-2 bar, replace the fuel filter housing.
If the malfunction occurs when the fuel level in the tank is low, check the correspondence between the actual fuel level and the instrument panel readings.
The fuel intake unit sucks in fuel through the Venturi tube located in its lower part. Check if the venturi hole is clogged (diameter 6-8 mm) dirt accumulated in the tank.
Check the quality of the fuel you are using.
Compare fuel with known clean fuel: gasoline, thinners, thinners, sulfuric acid (giving the fuel a whitish appearance), water or oil. If the fuel is contaminated, change it.
Replace fuel filter.
Bleed air from the high and low pressure circuits of the fuel system.