Injector Harness 411

Powerstroke diesel engines have gone in to Ford’s Super Duty trucks, E-Series vans and the Excursion since the mid 1990’s. Initially produced by Navistar, (formerly International Truck & Engine,) Ford took production in-house in 2011, today building the fourth generation in Mexico.

Known for good torque and horsepower, the Powerstroke has been a resounding success. Unfortunately it’s also known to have a few weaknesses, one of which is the injector harness.

The injector harness routes electrical signals to the injectors, ensuring fuel is delivered at the right point in the compression stroke. When those signals don’t get through the affected injector(s) won’t operate and the engine runs unevenly, or not at all. Injector harness problems have been widely reported with the 7.3 and the 6.0 liter Powerstroke engines.

7.3 Engine

The “Check Engine” light will be illuminated and the trouble code is “P1316”, meaning a fault with the injector driver module (IDM). A “Buzz” test will check all eight injectors are working, but not many home mechanics are equipped to do this.

The alternative is determine which injectors aren’t operating, (check the exhaust manifold temperatures,) and examine the harness connection supplying those cylinders. Often the connector will be found to have separated, although sometimes a poor connection has caused heating that burns or melts the connector block.

6.0 Engine

Here the problem is the harness routing. Over time it chafes, eventually leading to failure. Complicating matters, the damage is sometimes internal and not visible to the naked eye. Symptoms will usually be one or more injectors not working (though they will be on the same bank,) or random engine shut-offs due to the harness grounding internally.


While it’s possible to buy individual harness components it’s easier to buy a complete kit including valve cover gasket.

What tools are needed to remove a diesel fuel injector?


Removing your diesel fuel injectors may seem like a job for only a skilled mechanic but the truth is with the right tools, just about anyone with a little know how can remove their diesel fuel injectors. There are a few different tools that you will need to remove the fuel injectors from any diesel engine and with these tools, you can have your engine pulled apart in no time.

The first tool you will need is of course you run of the mill wrenches. This is to remove any covers, protective shields, and more that help to keep your engine enclosed. This type of tool is something that just about everyone has and there should be no reason to buy a new set. Wrenches are easy to come by and most injector covers use standard size nuts and bolts which means that you will not need to buy any special wrenches that are hard to find or useless for other jobs afterward.

The next tool you will need is of course what you will need to take the injector out themselves. This tool is ironically enough called a fuel injector remover. This tool offers a wide range of sockets, much like a ratchet set, that will fit injectors of any size. The set also includes the clamps and bars that you will need to create adequate leverage to remove your injectors. Depending on what company you purchase from, you may also find a simpler, less complicated tool. The less complicated tool is also a fuel injector remover but instead of complicated sockets and clamps, this tool is simply a tube in which you place your injectors then pull. If you feel at any time that you are not able to remove your injectors properly, you may want to call a mechanic to get some pointers.


Install Fuel Injector in Duramax Engine

Duramax engine

Whether you own an older or newer GM Duramax turbo-diesel, you may want to install a fuel injector to replace a tired one. It’s not overly difficult if you have some engine experience. Historically, early Duramax engines were prone to injector failure, requiring frequent replacement.

The Short Version – Steps to Install Fuel Injector on Duramax

  • First, drain the radiator coolant (put aside) and disconnect the negative terminal from your battery.
  • Remove the electrical connector from your air inlet duct on the left side of the turbocharger.
  • Disconnect all electrical connectors from your wiring harness and from the barometric sensor.
  • Take off the engine wiring harness clip before removing the connector for the glow plug controller.
  • Disconnect the crankcase ventilation hose. then disconnect the outlet duct for the air cleaner.
  • Remove the fuel filter and its bracket, along with removing the fuel lines from the injectors and their electrical wiring.
  • Clean away any debris near fuel injectors and fuel lines with a clean cloth or compressed air.
  • Take off mounting bolts for the fuel injector bracket.
  • Use injector removal tool and a flare nut wrench to take out the damaged fuel injector. Examine the injector copper washer and O-rings and replace when necessary.
  • Install the new injector, while fastening its mounting bolts for the fuel injector bracket.
  • Tighten mounting bolts with a torque wrench to 22 foot-pounds.
  • Re-attach injector electrical wiring, fuel lines and fuel line clips. Use a torque wrench to secure fuel line retaining nuts. Tighten to 30 foot-pounds.
  • Re-attach all remaining items by reversing the first six steps that detach these components. Don’t forget to put back the coolant you drained in the first step.

As you can see, the preparation and disconnecting phases are critical to successful installation of fuel injectors. Follow the sequence noted and reverse the steps in proper order to ensure a proper installation.

What is a fuel injection harness?

When it comes to building a custom fuel injection engine or replacing an older fuel injection engine with a newer counterpart, there is one piece of equipment made to greatly simplify the process, a fuel injection harness. This wiring harness is integral piece of your engine installation and is key in the ability to properly supply fuel to your engine.

How to Install Your Fuel Injection Harness

  • Start by positioning the wiring harness along each one of the engines fuel injectors.
  • Once in the correct positions begin snapping each electrical connection into the proper position on each of the injectors.
  • Carefully install the throttle body, paying close attention to each electrical connection.
  • Go back over each one of the electrical connectors to make sure they are securely in place.
  • Lastly, connect the negative battery cable.

Depending on the size and type of fuel injection engine you are working with there may be options available for a customizable fuel injection wiring harness. You can purchase a stock harness or in some cases have a modified harness made for you. A customized wiring harness can be built to accommodate wiring for electronic transmissions, computer controlled fan monitoring, the ability to retain emission components and much more. There are helpful options available to have color-coded wire, labels and convoluted tubing on different harnesses to greatly add to their ease of use during the installation process. When you are undertaking such a big and vital part of the engine installation process these modifications can add greatly to your peace of mind and help you get the job done in a safe and timely manner.


6.0L Fuel Injection Leak

When a fuel injector starts to malfunction, it can cause the car’s performance to quickly decline over time. Most owners will immediately want to learn more about the different types of issues that may be affecting the fuel injector. If owners discover that they do in fact have a 6.0L fuel injector leak, they should take some steps to repair the system soon. This can prevent bigger issues from developing at a later date. Owners may opt to simply replace the entire fuel injector, but there are ways to provide a temporary stop to any leak that has occurred. Ideally, these owners should have a mechanical background and experience working with their car before they take on this task.

It will first be important to run a quick diagnostic test on the fuel injector components to see if this registers a problem. Depending on the make and model of the vehicle, there are a few different testing kits that owners can use. For instance, they could decide to use a Ford IDS or other comparable diagnostic tool for this. It may reveal that there is some component within the injector allowing combustible gas to enter the fuel line.

Owners should try to narrow down the codes to identify the source of the leak. If there is an electrical malfunction elsewhere causing the leak, then fuses may need to be replace. It is also possible that a C-ring inside of the injector has corroded or become dislodged over time. This can be replaced if the C-ring can be dislodged using a pair of screwdrivers. This can allow the injector to form a consistent seal around the edges of the system itself.

Finally, it will be important for owners to prevent this kind of damage from occurring at all. Poor quality fuel may contain a considerable amount of impurities that may disrupt how the system is operating. This can allow dirt and other particles to get trapped within the injector, which may ultimately damage parts. Owners should make sure that they are using high quality fuel that will prevent this from happening.

Fix a 7.3L Injector Leak

In many cases, a fuel injector leak on a 7.3L engine is caused by a faulty fuel pressure switch. This is a fix that can easily be completed at home with just a few simple tools.

  • Fuel Pressure Switch

Though the fittings look like those on an oil sending unit, an oil sending unit socket cannot be used on a fuel pressure switch without taking off many parts. In order to avoid having to remove the engine mount as well as the turbo mount, use the ribs on a pair of channel locks to gently remove the fitting for the old fuel pressure switch.

Apply specially designed tape or sealant when installing the new part to help reduce the possibility of leakage. Tighten up the new fuel pressure switch by, again, using just gentle pressure with no squeezing to work the part into its socket. The tape or sealant that is used will help ensure a waterproof seal.

  • Filter Housing

In some cases, the O-ring is not replaced when the old filter is removed. This affects the seal that is supposed to be present. In other cases, this filter housing is not torqued down like it needs to be, resulting in a leak.

These two items are quick and easy places to start checking when this type of engine has a fuel injector leak.

Replace a 7.3L Fuel Injector

The 7.3L fuel injector is for the fuel injected eight-cylinder diesel engine. The Ford power stroke engine was produced from 1995 to 2002 and typically used in ¾ ton pick-up trucks and heavier. The fuel injectors on a Ford 7.3L diesel engine can be removed individually from the other injectors without having to remove the engines fuel rail.

What you’ll need:

· Engine oil

· Drain pan

· Set of socket wrench’s

· Rotunda injector sleeve brush #104-00934-A

· Injector remover #T94T-9000-AH1

· Injector replacement #T94T-9000-AH2

· Shop towels


1. Place an oil draining pan under each of the oil drains, open plug with a socket wrench, allow the oil to drain and replace the plug. Draining the oil will prevent any oil from getting in the combustion chamber while replacing the fuel injector.

2. Disconnect and remove the valve cover using a socket wrench, unplug the electrical connector from the fuel injector and remove the drain plugs from the oil rail and fuel rail. Remove the retaining screw for the oil deflector and disconnect the oil deflector. Remove the retaining bolt for the fuel injector.

3. Place the fulcrum of injector remover above the cylinder head and below the hold-down plate of the fuel injector. Fasten the remover screw in the hole of the injector plate, tighten the screw to remove the fuel injector from the injector bore and discard the copper washer.

4. Use the Rotunda Injector Sleeve brush to clean the injector bore and remove any debris or sealant residue. Lubricate the new fuel injector with clean engine oil and mount the new copper washer on the injector.

5. Gently push the fuel injector into the injector bore to set the O-rings. Put the open end of the injector replace between the fuel injector and the hold-down plate. Fasten to the cylinder head with the retaining bolt included with the tool kit. Tighten bolt to completely seal the fuel injector and disconnect tool from the cylinder head.

6. Reinstall the oil deflector and tighten the mounting bolt to 108 inch-lbs using a torque wrench. Tight the drain plugs from the fuel rail to 96 inch-lbs and the oil rail drain plug to 53 inch-lbs. Reconnect the wiring harness for the fuel injectors, install the valve cover and replace the oil with new oil.

Replace a 6.0L Fuel Injector

6.0L fuel injector can easily get gummed over time, requiring a replacement.

The first step is to remove the fuel injector valve cover and then remove the CAC tube underneath. Additionally, a repairer needs to remove the wiring associated with the glow plug control module as well as the ICP sensor.

The second part is to then remove the standpipe from its position. The pipe could be long or short, depending on the truck engine configuration. The standpipe needs to be separated if it is a long version. Once the oil rail is removed then the long lower part of the standpipe can be put back into place. The oil rail bolts can then be removed and lifted carefully. Watch out for draining oil.

The third step is to position a 19mm socket so that it is secure on the injector connector. With firm pressure, the socket should be pressed in until the injector lock tabs release. The injector connect will then be free to be pulled up. Now the injector hold down clamp can be removed. The parts will come out of the injector bore as they are loosened.

At this point the inside of the injector bore should be examined to see if any of the copper seal or o-rings need replacement. If not, the new injector can be greased with clean engine oil and inserted after the hold down clamp is attached to it. The injector connector o-ring can then be greased and pushed into position until seating with a click. The position should be the same as the other injector connectors.

Next, before the oil rail is reinstalled, a bit of engine oil should be applied to the new injector top. At this point the rest of the parts removed can be reinstalled back in their original sequence. Engine ignition could take a while before the engine turns over after a change due to significant air in the system.

Replace Ford 7.3L 94-97 Injector

Replace Ford 7.3L 94-97 Injector

Draining the HPOP reservoir or the crankcase is not necessary prior to replacing this type of fuel injector. Start by removing the engine cover, CCV assembly, air filter, intercooler tubes and turbo intake hose. In addition, make sure to unplug the wiring harness before removing the side valve cover on the driver’s side of the vehicle. Start with the driver’s side first, where there is more room to maneuver yourself and your tools.

To unplug old injectors, flip down the clips holding them in place. Proceed to pull up on the wire plug in order to remove glow plugs. Then, gently take out the gasket and set it aside to be reused later.

Oil spouts will need removed with a five mm wrench. Your old oil spouts will be placed on the new injectors so lay them in a safe place where you can easily find them later. Next, detach each injector’s lower retaining bold with an eight mm socket. Leave the upper bolt alone because the injector collar easily slides away from the upper bolt.

Begin working with the rear injector and move forward since the engine’s angle permits most of the oil and fuel to drain into the last cylinder. Apply pressure with your prybar between the head’s top and the injector collar. Carefully remove the rear injector when it becomes free from its spot and continue on removing the remaining three injectors.

To soak up oil seeping from the holes, stick rags in the holes and crank the engine by hand several times. Also clean injector holes and make sure all copper washers were removed when you took out the injectors.

Using your 10 mm socket, remove glow plugs and then begin installing the new injectors. Lubricate them with engine oil before placing one in its hole. Seat each injector by giving it two or three good smacks with your hand once you have it firmly in the hole. Use the rubber mallet to secure all four injectors.

With your eight mm socket, torque the lower retaining bolts to 120 inches/pound and put back all oil spouts. Put the valve cover gasket back on and plug in all injectors, making sure the metal clips are secure. When replacing the VC cover, just tighten a couple of bolts since you still need to replace the old injectors on the passenger’s side of the car.

After reinstalling glow plugs, hook up the main wire harness and everything else you removed at the beginning of this project. Rebuild oil pressure by cranking the engine for about 25 seconds. Allow the starter to rest for a few minutes and then try another 15 second crank. If it doesn’t start, just let the starter rest a little longer. You will be able to hear the new injectors clicking prior to the engine firing.

Replace Ford 6.0L 04-09 Injector

Cut away diagram of a fairly basic fuel inject...

Cut away diagram of a fairly basic fuel injector for the fuel injection article (Photo credit: Wikipedia)

It is very simple to replace an injector on your Ford 6.0L engine. First, you should gather the necessary tools. You’ll need an Injector Release Tool, that can be found at any Ford dealership and most auto supply stores. You’ll need a High-Pressure Supply Tube Remover, also available from dealerships and most auto parts stores. You may also wish to have some 15W40 motor oil on hand, as well as some brake cleaner.

After you gather the supplies, it’s time to get to work. Start by removing the valve cover from your engine. This is a quick and easy process, and simply involves loosening a few bolts. Then you need to disconnect the electrical connector for the actual fuel injector. Following that,you need to loosen the crankcase-to-head tube assembly, then position the crankcase-to-head tube and separate the tube. Once this is done, allow the lower section to go back down.Then remove the bolts and the high-pressure oil rail. Then you can remove the crankcase-to-head tube and inspect the D-ring seals for any type of damage. If you notice any damage, you should replace the crankcase-to-head tube.You should also remove the port plug from the high-pressure oil rail and inspect theO-ring seals for damage. Again, if you notice any damage, replace the port plug.

After these steps are complete, it’s time to remove the injector itself.Using the Injector Release Tool, push the fuel injector electrical connector out of the rocker arm carrier. Then insert clean shop towels in the oil drain holes adjacent to each glow plug. Then you can loosen the bolt and remove the bolt and fuel injector hold-down assembly and the fuel injector itself.

A few notes to keep in mind when doing this project: When you are completing this job, you should always ensure that you NEVER remove the oil rail end plugs or acoustic wave attenuator port fittings, as service parts are not available to support these components.You should also never use air tools, as they can damage the components that you are dealing with. And make sure you account for all snap rings and replace them properly when putting the engine back together. Missing snap rings can cause irreparable engine damage. In addition, if you find engine coolant in the combustion chambers, it may be necessary to install a new injector sleeve.