How to Remove and Install Fuel Injectors

Many of us have noticed a fuel smell from our cars, especially on a warm day. Most likely the fuel smell is due to a line, connector, or regulator vacuum line leaking, but it could also be due to an injector body leaking. Given the age of our vehicles, it is often all of the above.

Consequently, the importance of being thorough on inspection is critical. In this article, I will cover the inspection and the removal and installation of the fuel injectors in a 2.3 liter turbo motor. My base of reference will be my own 1986 SVO. Other SVOs and turbo 2.3s may be slightly different, consequently, a little American ingenuity and a decent set of shop manuals should be kept on standby for this project. Good Luck!

Preparation and Diagnosis

1. Set aside some time, at least a Saturday, for this project.
2. Get all the necessary parts:

• fuel injector replacement o-rings x 8


• upper to lower intake gasket


• fuel feed and return line o-rings x 6 (these go inside the fuel feed and return lines where they attach to the fuel rails)
  
• duck bill clips x 2 (only one for the 84-85)


• fuel injectors x 4, if necessary


• Loctite 242


• motor oil--to coat the o-rings with during installation


• a can of electronics safe cleaner and solvent

Ford can sell you all these parts, although for parts like the solvent, motor oil, and the injectors, it may be smarter to purchase them elsewhere.

1. Lay out all the necessary tools:
• a complete metric socket set


• a set of metric allen wrenches, specifically a 5mm wrench
• a Quick Disconnect tool for Fords


• Phillips and standard screwdrivers


• a 15/16" box-end wrench


• a decent set of shop manuals


• lots of rags


• a flashlight


• pliers
2. Wash the engine as a completed assembly and allow it to dry before you start any disassembly of the motor. Concentrate on the injector area being sure to remove all dirt and debris. This might be done a few days prior to the repair.
3. Determine where the fuel is leaking from on the vehicle. Be sure to check the fuel lines running from the tank to the motor. Be especially aware of leakage at all connectors including the filter assembly (in from of the tank), secondary pump (84-85 only on the passenger frame rail), and the fuel charging assembly on the motor. Any signs of leakage will require immediate repair! If the leakage is traced to an injector, mark this injector for later identification and testing.

Getting Started

1. Disconnect the negative battery terminal.
2. Remove the intercooler assembly. This is fairly simple and self-explanatory: just loosen the two hoses and remove the attaching bolts. Don't forget about the bolts in the back!
3. Gently pry on the throttle cable to remove it from its ball and socket joint on the throttle body. Remove the bolt attaching the throttle cable to the upper intake and position it out of the way. If your car has cruise, this will be a somewhat more complex process. Refer to your shop manuals for specific instructions.
4. Remove the exhaust tube from your Exhaust Gas Recirculation, or EGR valve. This is located on the back side of the upper intake and will require a 15/16 open-end wrench. To do this, first loosen the end on the exhaust manifold about 1/2 turn then completely remove the end of the EGR valve.
5. Unplug the connector going to your Throttle Position Sensor, or TPS. This is located at the back of the throttle body on top of the valve cover.
6. Remove the vacuum lines attached to the upper intake and position them out of the way.
7. REmvoe the PCV valve from its hose. The hose is located just above the distributor cap.
8. Remove the bolts attaching the upper intake to the lower intake. Gently remove the upper intake. Stuff a rag into or tape up the lower intake ports to prevent any material from entering the intake. Carefully clean the old gasket material from both manifolds. At this time, it might be wise to use some of your electrical parts cleaner to desludge the throttle body.

Fuel Charging Assembly

1. Relieve the fuel pressure by depressing the schraeder valve on the fuel rail. One some early SVOs, the schraeder valve will be located on the fuel line just above the brake booster as the fuel supply comes away from the firewall.
2. It would be wise to check for any dirt or debris at the base of the injectors. If any is evident wash it off with some electrical solvent or wipe it off with a clean rag.
3. Disconnect the electrical connector at each injector, making note of the location of each plug. Disconnect the Engine Coolant Temperature or ECT sensor. Position the wiring harness out of the way.
4. Remove the high and low pressure fuel lines from the fuel rails and position them out of the way. These lines will be attached by duck billed clips or a Ford Quick Disconnect fitting. The quick disconnect fitting requires a special tool for removal. The duck billed clip can be disconnected by prying upwards on it with a screwdriver. Never re-use a duck billed clip. Wrap the open fuel lines with a sandwich baggie over the hose ends as they will drip fuel for some time and to keep them clean.
5. Remove the bolts that attach the fuel rail to the lower intake. This is straightforward on 85.5-86 models as two 10mm hex bolts are on top of the lower intake manifold and can be reached easily from above. On 84-85 models, one 8mm hex head bolts is located on the side of the lower intake by the distributor cap. Removal of the distributor cap is recommended to ease the removal of the fuel rail on 84-85 models.
6. Gently pull backwards on the fuel rail to dislodge the injectors. Try to pull the injector body out of the manifold, keeping them in the fuel rail. If an injector does pull out of the fuel rail, it will spill a substantial amount of gas on your fuel rail. Keep a few rags handy to sop the fuel up.

Installation

Installation is basically the reverse of the removal with a few exceptions:

1. If re-using the old injectors, I suggest having them professionally cleaned and inspected. Always replace the injector o-rings!
2. Inspect the fuel rail with a magnifying glass for any pin-hole leaks.
3. Coat the o-rings on the new injectors with engine oil to ease installation.
4. When installing the injectors, be sure the new injectors are properly seated in their bores before tightening the fuel rail to the lower intake.
5. It may be wise to replace the fuel pressure regulator at this time since it is much easier to get to when disassembled, and they do commonly go bad. In any case, replace the o-ring and seal on the pressure regulator and use Loctite 242 on the 5mm allen head bolts.
6. Also, one could do a little cleaning and detailing work to both intakes and the fuel rail while they are apart. Be careful though, these parts are irreplaceable!
7. When the car is back together, turn the ignition key on and off a few times to refill and pressurize the fuel system; drive and inspect for leaks.