10 4 PL FUEL SYSTEM ELECTRIC INTANK FUEL PUMP WITH IN BUILT PRESSURE REGULATOR : The electric fuel pump is located inside the fuel tank. It is a positive displacement pump assembly driven by motor to provide continuous flow of fuel to the high pressure fuel system from fuel tank.This pump is inbuilt with pressure regulator. The pressure regulator maintains the pressure in fuel line. A return line is provided after fuel filter so that incase if pressure tends to rise, excess fuel returns back to fuel tank.This ensures the constant operating pressure of 3.5 bar in the fuel rail.The fuel pump consists of check valve tomaintain pressure in the fuel feed line evenwhen the fuel pump is switched OFF. Fig. 12. Removal / Inspection : 1. Before removal, check fuel pump for operation as follows : a) Remove fuel filler cap. b) Release the fuel system pressure as mentioned above for ‘removal of tank’. c) Turn ignition switch‘ON’ d) Checkwhether fuel pump is runningby listening for sound at fuel filter inlet. e) If no sound is heard, measure voltage between fuel pump electrical connector wire to chassis ground.The voltage should be approx.12V. f ) If voltage is not correct, check for fuel pump relay and relatedwiring harness. g) If you do not measure 12V, check for continuity between fuel pump connector terminal wires (battery) and (ground). h) If there is continuity, replace fuel pump. i) If there is no continuity, repair ground circuit. j) For fuel pump removal fold the carpet between jump seat floor and open the plastic lid located under the floor carpet. Disconnect electrical connectors. Release the fuel system pressure as already explained in fuel tank removal. Disconnect the quick fix couplings by pressing the twotabs. Loosen fuel pumpmountingscrews. Push the ring asidewhile taking pump out. k) Check fuel pump filter for evidence of dirt and contamination. If so, cleanandcheck for presence of dirt in fuel tank. 2. Check fuel pump for pressure : a) Release the fuel system pressure as mentioned above for ‘removal of tank’. b) Disconnect negative battery terminal. c) Remove fuel delivery line connected to underbodybundy tube. d) Connect fuel pressure gauge(having a range of 0 - 10bar) to the delivery line. e) Check that battery voltage is @ 12V f ) Turn ignition switch ON to operate fuel pump and after 2 seconds turn it OFF. Repeat this 3-4 times andmeasure fuel pumppressure. It should be 3.5 bar. g) If it is notwithin specification, replace fuel pump. ● If the pressure is high, check for a) restricted fuel return line b) If the return line is clean, replace fuel pump. ● If the pressure is too low :- a) Block return line and check if pressure rises. b) If pressure does rise, reassemble fuel pump. c) If pressure does not rise, replace fuel pump or check for leakages.. 3. After checking fuel pressure, remove fuel pressure gauge. 4. Connect fuel delivery pipe back to original position andensure thatquick fixcouplingsareproperly fitted. 5. With engine OFF and ignition ON check for fuel leakage. Warning : Unless replacement is necessary, fuel pump, fuel level gauge should not be removed from the tank since the rubber parts i.e. gasket, seals etc.may get exposed to air, light andmay become hard. Never apply an excessive force to the fuel pumpnipple or leadwire.This may result in bent or poor contact. Assembly : Assemble the pump in reverse order of removal as explained in 1.j. (above) Fig. 12
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