How to Replace a Fuel Injector in a Nissan Sentra

The fuel injector in a Nissan Sentra mixes fuel with air under pressure and rendered carburetors obsolete during the late 1980s. One advantage of a fuel injector is the programmable firmware that allows the same hardware to work with different fuels. The fuel injector assembly includes only the nozzle and valve; it still requires a pump to deliver fuel into the engine.

Instructions

1

Determine which fuel injector your Nissan Sentra will need. This depends not only on the make and model, but also the engine size. Models made from 1982 to 1986 may have a 1.5L, 1.6L or 1.7L diesel engine and 1986 to 1990 use 1.6L engines. Models made from 1991 to 1994 may have a 1.4L, 1.6L or 2.0L engine.

2

Look at later versions of the Nissan Sentra. Models built from 1995 to 1999 may have a 1.6L or 2.0L engine, and engine sizes for 2000 to 2006 models are 1.8L, 2.0L and 2.5L. The current generation debuted in 2007 and is available with a 2.0L MR20DE engine.

3

Disconnect the negative battery cable with a socket wrench and relieve the fuel system pressure. Disconnect the vacuum hose and remove the intake manifold collector from the fuel pressure regulator.

4

Detach the fuel hoses from the fuel rail with a socket wrench and disconnect the fuel injector electrical connectors. Remove the fuel rail mounting bolts with a socket wrench so you can separate the fuel rail assembly from the intake manifold with the fuel injectors still attached.

5

Push on the fuel injector tail piece to separate the injector from the rail. Discard the fuel injector O-rings.

6

Lubricate the new O-rings with a small amount of clean engine oil and install the new fuel injector by reversing the removal procedure. Use a torque wrench to tighten the fuel rail mounting bolts in two stages. First, torque the bolts to between 84 and 96 inch pounds and then torque them to between 15 and 20 foot pounds.