How to Replace a Fuel Injector in a Pontiac Grand Prix

by Editorial Team

The Pontiac Grand Prix mixes fuel and air under pressure with a fuel injector. Carburetors previously performed this function passively but were rendered obsolete by fuel injectors in the late 1980s. A fuel injector's programmable firmware allows it to handle different fuels. A fuel injector consists of only the nozzle and valve; it still requires the pump to pressurize the fuel.

Step 1

Determine which fuel injector your Pontiac Grand Prix will need. This depends not only on the make and model, but also the engine size. Models made from 1962 to 1968 will have a 389 cubic inch (ci), 400ci, 421ci or 428ci engine. Models built from 1969 to 1972 may be equipped with a 400ci, 428ci or 455ci engine.

Step 2

Look at later generations of the Pontiac Grand Prix. Models made from 1973 to 1977 may have a 231ci, 350ci, 400ci or 455ci engine. Models manufactured from 1978 to 1987 have 231ci, 252ci, 265ci, 301ci, 305ci and 350ci engines. Models made from 1988 to 1996 can be equipped with a 2.3L, 2.8L, 3.1L or 3.4L engine.

Step 3

Examine the most recent versions of the Pontiac Grand Prix. Models made from 1997 to 2003 will have a 3.1L or 3.8L engine. The last generation was produced from 2004 to 2008 and had a 3.8L, 3.8L supercharged or a 5.3L engine.

Step 4

Disconnect the negative battery cable with a socket wrench and relieve the fuel system pressure. Remove the fuel injector sight shield with a socket wrench and disconnect the fuel send and return lines.

Step 5

Remove the fuel pressure regulator vacuum hose and ignition coil wires from the coil. Disconnect the electrical connectors from the fuel injectors. Remove the fuel rail mounting bolts with a socket wrench and release the retaining clips on the fuel injectors. Pull the fuel injectors from the fuel rail. Discard the old O-rings.

Step 6

Install the new fuel injectors by reversing the removal procedure. Coat the new fuel injector O-rings with clean engine oil. Use a torque wrench to tighten the fuel rail mounting bolts to 7 foot pounds and torque the mounting nuts for the fuel injector sight shield to 27 inch pounds.

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