Nissan Sentra/Pulsar/NX 1982-1996 Repair Guide

Injection Lines



See Figures 1 and 2

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Fig. Fig. 1: Diesel engine injector line routing

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Fig. Fig. 2: Always use two wrenches when loosening and tightening injector lines

Fuel injection systems remain under pressure after the engine has been turned OFF. Properly relieve fuel pressure before disconnecting any fuel lines. Also observe all safety practices outlined previously in the Fuel System Safety Precautions. Failure to do so may result in fire or personal injury.

  1. Following proper procedures, relieve fuel system residual pressure.
  3. Note the firing order of the injection pump and the line locations for easy reassembly (the lines are held together by clamps to dampen vibration, so it is almost impossible to mix them up unless they are separated). Install a wrench on the flats of each nozzle or injection pump fitting. Then, install a wrench on the injection line flare nut. Turn the flare nut loose while opposing the torque with an equal force in the opposite direction on the pump or nozzle fitting.
  5. Remove the tubes, which are clamped together to dampen vibration, as an assembly. Carefully plug all openings to keep dirt out of the system. If it is necessary to remove the injector spill tubes, unclamp and slide off the hose at one end. Then, remove the retaining nuts from the tops of the injectors and remove the spill tubes, noting the direction of installation.

To install:
  1. Install the spill tube assembly, install the retaining nuts, and torque them to 29-36 ft. lbs. (39-49 Nm). Inspect the return hose, replacing it if necessary. Install it onto the spill tube assembly and clamp it tightly.
  3. Install the injection lines in their original firing order. Torque the flare nuts to the pump and nozzles using a backup wrench to oppose the torque. Torque the flare nuts to 16-18 ft. lbs. (21-25 Nm).
  5. Loosen the bleeder cock (equipped with a wingnut) near the top of the filter unit, place a metal cup underneath it, and then activate the priming pump by repeated depressing the top of the unit. When fuel without bubbles comes out, close the cock.
  7. Loosen the fuel return hose at the injection pump. Have someone turn the engine over until fuel without bubbles comes out of this fitting. Then, reconnect the hose securely.
  9. If the engine will not start, have someone crank the engine as you loosen each injector line at the pump and allow fuel to spray out until it is free of bubbles. Then, retorque the flare nuts.