How to Change Your Fuel Injector - Got Fuel?

Likewise, you can then carefully pry the bottom of the righthand runner assembly away from the intake manifold.

The lefthand (driver-side) lower runner bolts are tough to access, so we chose to leave them untouched and only remove the upper runner-to-plenum bolts and the plenum, while leaving the lefthand runner assembly in place.

As we lifted off the plenum, we were sure to unplug the air temperature sender connector from the underside of the plenum.

Here's the right-side sixth runner-to-manifold bolt, shown with the plenum and runners removed. You'll have to use care and patience when removing it with the plenum and runners still installed.

Two fuel lines to the fuel rail and their retaining bracket must be disconnected before you can lift out the fuel-rail assembly. Be careful when loosening these lines since the fuel can be under significant pressure. Use caution and eye protection, and loosen them a little at a time until the pressure has been relieved. Use a 51/48-inch flare (line) wrench and a 31/44-inch open end to break loose the fittings. Two T40 Torx bolts hold the fuel line bracket to the intake manifold, and must be removed to allow you to lift out the fuel-rail assembly.

Carefully remove the vacuum line from the fuel-pressure regulator.

These tuned port injection engines use a "9th injector" bolted to the left-side runner assembly for cold start enrichment. GM refers to this injector as a "cold start valve," and it is no longer available. So we left this 9th injector in place and disconnected the feed line in order to allow us to remove the injector rail.

With the plenum and both side runners removed, disconnect the electrical connectors at each injector by pressing in on the retaining tang. While the locations for the connectors are intuitive, they are also critical, so it's worth a few minutes to label each connector in order to be sure you reassemble it into the proper location.

With the removal of the four bolts holding the fuel rail in place, you can now lift out the fuel rail/injector assembly. Note that the driver-side runner assembly has been removed to allow for a clearer photo. At this point, we now prepare for the actual disassembly of the fuel-rail injector assembly.

Small quarter-turn retainers hold each injector in place. The injector on the left shows the retainer in the disengaged position; the injector on the right shows the retainer turned to the engaged position.

Careful use of a screwdriver will rotate and disengage the retainer.

With the retainer disengaged, you can now lift out the injector. you'll have to tug slightly in order to overcome the friction of the o-ring that seals it in place.