How to install a fuel injector

This webpage describes how to replace the fuel injectors on a Ford 2.3L engine in a Ranger pickup. Other models and years of the 2.3L engine may differ. The fuel pressure line is pressurized to 45 psi of pressure so you must take extra precaution in releasing the fuel pressure before working on the fuel injection. Have a fire extinguisher available!

Before you start you must have a repair manual for your 2.3L that describes how to release the fuel pressure from the fuel injector rail. There are several methods and how you do it, depends on what tools you have. Releasing the fuel pressure is beyond this webpage's purpose and I will leave it up to you to determine the safest method for your application. I've included some pictures of my 2.3L taken apart and some notes on the pitfalls that you may encounter.

Disconnect the battery positive lead

Unplug the circled connectors and vacuum lines. This picture was taken out of order after the intake manifold was removed!

The connectors are tricky as they have snap-on clips on both sides. Use a small screw driver to open each side of the snap clips.

After failing to get a replacement gasket that goes between the throttle body and intake manifold at the local parts sources, I went to the Ford dealer. According to the local Ford dealer, the gasket is obsolete and no longer available BUT he did have the last one in stock. I've scanned it in so that if you need one, you can make one from the scanned image

Undo the bolts on the EGR valve, Intake manifold and the fuel rail ONLY when the fuel pressure is released.

There are two bolts on the EGR valve to remove. The bottom one is a pain and I had to play with it from the intake manifold side. The intake manifold has 5 bolts holding it in place of which 3 are threaded studs with an extra nut on to hold other things. So you have to unscrew 3 nuts before you can unscrew the bolts/studs holding the intake manifold.

Once the 5 bolts/studs are removed, you should be able to swing the upper throttle body unit on top of the master cylinder like in the picture.

Upper throttle body swung out of the way over the master cylinder

Carefully disconnect the fuel injector's electrical connectors. They are similar to the previous ones with two clip on latches on either side. You can rotate them to make it easier to remove. Mark each connector with the cylinder number for re-installation.

Fuel Injector connectors

You MUST release the fuel pressure on the fuel injector rail before removing the 2 mounting bolts! Otherwise you will have up to 45 psi of gasoline spraying all over the place - this is a BAD thing. Consult your repair manual for a safe method of releasing the fuel pressure. There are several methods and each method is dependant on what tools YOU have available.

Location of fuel rail

Once the fuel pressure is released, remove the two bolts holding the fuel rail. Place a rag around the fuel injectors because there will still be some gasoline left in the fuel rail. Then gently rock the fuel rail to release the fuel injectors from the intake manifold and fuel rail. The fuel injectors are "squeezed fit" in to both the intake manifold and fuel rail using just rubber O rings.

Apply some clean motor oil to the new injector O rings and carefully push the injector into the intake manifold. Once all the injectors are in the intake manifold, then push the fuel rail onto the injectors. It's not too hard to do. Finally screw in the 2 mounting bolts, tighten and install the fuel injector electrical connectors.

Re-install the upper throttle body in the reverse order that you removed it. Ditto for the connectors. Connect the battery positive cable and fire up the engine. IMMEDIATELY look for fuel leaks and be prepared to shut down the engine. You will have 45 psi of fuel squirting out on a running engine, so if there is a leak, you will not have much time!

Here is another website that provides tips on swapping out the fuel injectors

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Copyright February 2011 Eugene Blanchard