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© 2001 Brian F. Schreurs
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We bought our fuel injectors from Summit Racing; we went with Ford Motorsports injectors (#M9593A302). This step also required a replacement upper intake manifold gasket (Fel-Pro #MS94555) and the EGR gasket (Fel-Pro #72649). Bigger fuel injectors also require a bigger mass airflow meter. We installed a 77mm Pro-M MAF as part of the supercharger project. This project requires a fuel line disconnect tool; we used Lisle #37000.

Our starting point. All that has to go back in, plus a supercharger.

Start by removing the airbox. Our car already had a custom cold air induction system so our airbox was long gone. Because of that, we really can't offer much advice for removing the stock arrangement. For us, it was a matter of removing our custom brackets in the fender and unbolting it from the mass airflow meter. Then, wiggle it out from underneath -- not a lot of fun.

If you are doing this in preparation for a supercharger, you'll need to remove the air inlet temperature sensor. It's stuck, trust us. But it's housing is hexed for a 1" wrench and it unscews readily enough with some torque put on it. Don't forget to unplug the AIT sensor before removing it. The tube connecting the MAF sensor to the throttle body is just held on with two hose clamps; unplug the MAF and remove the MAF/inlet as an assembly. If you're not installing a supercharger, you don't need to remove the AIT sensor; just unplug it and remove the inlet tract.

Remove the strut tower brace -- that big bar that gets in the way of everything. It is held on by eight 10mm bolts.

The throttle body is actually coming out with the upper intake, so unplug everything from it.

Then disconnect the cables on the other side.

Looking for these? Hahahahaha.

Sneaky buggers, hiding more connections where you can't see them!

Unplug the idle air control valve, the throttle position sensor, and the EGR.

Remove the throttle cable. It has a little peg on its end with a flat spot. Twist it so that that flat spot on the peg corresponds with the indent in the housing and remove it. The cruise control cable, right next to the throttle cable, just snaps off. The bracket that holds the cable to the intake manifold is 10mm.

Remove the EGR valve. Two 13mm bolts hold it to the intake, and there's a gasket between them. It's a stupid gasket, could be one of three listed in the parts books. Most counter workers don't seem to be able to handle this; bring in the old one to match it up. Our part number is listed at the beginning of this page. Before you get any crazy ideas, reusing it doesn't work. Not that we tried or anything. We just heard about it, uhhhhh, from a friend. Yeah.

Remove the intake manifold. Let us know when you're done.

Ohhhhhhhh all right... we'll help. There are two 13mm bolts at the front of the intake. On the back, there's a cable bracket held on by an 11mm nut. That stud is also a bolt, and is 13mm. Then, it looks like the manifold should come off, but it won't. The secret, not discussed in Haynes or Chilton's, is hiding under that cosmetic plate that says "5.0 HO". The plate is held by two T-20 Torx bolts; under that is the secret: two more 13mm bolts! Now the upper intake manifold will come off!

As you remove the intake, there is a vacuum tee located near the fuel pressure regulator. Two lines connect from that tee to the intake manifold; they need to be unplugged. They're probably a little hard to remove, but they'll surrender. Also, there are a couple of lines on the underside of the intake that you can't see until the thing is in your hand, and there's another line on the back-driver-side of the manifold. Disconnect them all.

Take a moment to jam rags into the lower intake manifold. This will prevent garbage from getting in there and chewing up a valve.

With the upper intake out of the way, it's actually possible to see the fuel system. The fuel rail will have to come off to get at the fuel injectors. Release the fuel pressure by pushing in the schrader valve. It's located on the fuel rail.

At the connection where the fuel line enters the fuel rail, there's a safety clip. It just pulls off. Then, use a special fuel line disconnect tool to disconnect the two fuel lines. The upper hose requires a 1/2" disconnector; the forward line requires a 5/8" disconnector and will dribble a small amount of fuel.

The fuel rail is held to the lower intake manifold with four 8mm bolts. Try to be careful as you remove them, because sometimes the steel bolts will take the aluminum intake threads with them. Ford, of course, doesn't use standard-size bolts here, so replacing them is basically impossible. If they get stripped or otherwise damaged, you'll have to Helicoil them.

Unplug all eight electrical connections to the fuel injectors.

Lift the fuel rail. The fuel injectors will come with it.

We use the Lisle fuel line disconnect tool for its intended purpose.

For each fuel injector, wiggle it a little and it'll pop off. Each one will squirt a little gas, so this isn't the best place to take up smoking. Replacing them is easy -- pop the new injectors back in place. Be sure to put a little lubricant (we used 20-weight engine oil) on the O-rings.

Leave the protective caps on the fuel injectors until they are in their final position. Get the fuel rail and injector assembly positioned to nearly where it has to go; just before pushing each injector into place, remove the cap and lubricate the O-ring.

Reattach the fuel lines.

At this point, if you are doing a supercharger installation, stop here. Many steps in the supercharger project are easier with the intake removed. Once the intake will no longer interfere with anything, continue with the reassembly.

With the plugs, lines, and screws removed, the entire rail with injectors lifts right up.

One skanky OE fuel injector.

Reattach all the various and sundry vacuum lines to the intake manifold. Slide the new intake gasket between the halves and set down the manifold. Reattach all of the bolts.

Reattach the EGR using a new gasket.

Reattach the throttle and cruise control cables.

Plug in the IAC, TPS, and EGR wiring.

Reattach the strut tower brace.

Reconnect the air inlet system.

Yay! The car has new fuel injectors! Hooray!

Keep in mind that most cars don't have any use for bigger fuel injectors, so this isn't a mod to be done by itself. We did it as part of this Mustang's supercharger project, so we were already making several other mods that complement the injectors, such as the bigger MAF and the faster fuel pump. Carefully weigh your car's actual needs before pursuing this project.