Ford 7.3L 98-99 Injector Swapout Steps

First ratcheting socket wrench, made by J.J. R...

First ratcheting socket wrench, made by J.J. Richardson, 1863. (Photo credit: Wikipedia)

Ford 7.3L 98-99 Injector Swapout Steps

The first part of an injector swapout requires the removal of the valve cover. Once the chassis is opened, then the repair requires the removal of the CAC tube as well as the various control module and sensors to get the valve cover free of the assembly. Note that some of the securing bolts can be a bit stubborn due to the evaporator casing being right nearby.

With the first step completed, the standpipe then needs to be removed. With the pipe out of the way, the oil rail can then be addressed. The oil rails can be loosened and drained into the cylinder head to catch the oil in them. A socket wrench can then be used to unlock the injector connector locking taps. This allows the injector connector to be moved.

The injector hold down clamp bolt then needs to be removed. Once loosened, the injector itself will float out of its bore. This allows the mechanic to examine the injector’s o-rings and copper seals for damage.

A new injector can be inserted with new oil, reversing the steps by using the clamp to keep the new injector in place. With a new connector o-ring lubricated, it too can be inserted. More oil should be added as the oil rail is put back into place. The covers and sensors can then be installed back on and closed up.

Once complete, expect starting the engine to take a bit. The assembly has to push out all the air that it got exposed to and re-assert a vacuum again. Once the air purges, then the new diesel injectors will work and flow accordingly. A bit of exhaust smoke can be expected in the first two dozen miles.

EGR Valve Cleaning

Vacuum actuated drive to switch a valve to the...

Vacuum actuated drive to switch a valve to the exhaust gas recirculation (EGR) system (Photo credit: Wikipedia)

The Exhaust Gas Recirculation valve, or EGR for short, is responsible for the recycling of noxious emissions and placing them on a second run through your car’s engine. If the EGR valve is going or gone, your engine will be experiencing all kinds of issues, from a rattling noise to fuel inefficiency where it’s just guzzling the gallons and eating your wallet every few days. Since other things can cause similar problems in the engine, the only sure fire way of eliminating the EGR valve is by removing it, shaking it, listening, and cleaning it.

Cleaning the EGR valve is a simple six step procedure, simple enough if you can and are willing to identify the right parts of your car or truck’s engine and then take it apart. The EGR valve will be in a slightly different location depending on the make and model of the car or truck, but generally it will be to either side of the main engine block and the ignition control module. It might be cylindrical and vertical or horizontal and almost UFO shaped.

Once you have figured out where the EGR valve is, remove the vacuum line that connects it to the valve to ignition module. Then remove the electrical harness that provides power to the valve and surrounding area. Finally unbolt the valve itself.

Shake the valve. A side to side rattle means the valve is probably still good to use, but this isn’t a full proof detection method. No rattling means the valve definitely needs to be cleaned and hopefully will still be usable afterwards. Take the gasket off and check for problems with all the parts at this point. If it all looks good, just set it aside.

Carb cleaner in a bowl is perfect for soaking and cleaning the valve, unless there’s electrical components; then you will have to clean it by hand. An overnight soak otherwise should do the trick. The following day put everything back the way you found it, and you should be good to go.

EGR Cooler Replacement

MTU Integration EGR in engine design

MTU Integration EGR in engine design (Photo credit: Tognum: MTU & MTU Onsite Energy)

Replacing the EGR cooler is commonplace around 50,000 miles on Ford 6.0-liter engines and at varying mileage on others. The problem stems from the type of cooling passages used in the coolers, both EGR and oil. The passages are similar in size to that used in the radiator or heater core.

Consequently, the Ford Power Stroke 6.0-liter diesel engine has acquired a bad reputation. However, this is undeserved. This reputation stems from Ford and International’s failure to address some simple issues that have the potential to cause catastrophic engine damage. Why–this is a mystery you can only speculate.

Consider that the Ford 6.0 produces more power, better torque curve, is much quieter and far more fuel efficient than the previous 7.3-liter, or the Duramax and the Cummins engines. It does so using four valves per head and advanced varying turbo geometry. Correct these few problems and you have a superior engine.

Replacing the EGR and oil coolers is not a complicated process, just time consuming. The EGR cooler attaches to the passenger inboard side of the intake manifold while the oil cooler is under the center rear oil filter housing. Due to the number of parts and O rings involved, purchasing a service manual is a prerequisite for all but the experienced technician. With the manual, a novice can accomplish this job in four to five hours with common tools and save thousands of dollars.

The job of replacing these items entails draining the radiator, removing the upper hoses and loosening the shroud, removing the batteries, removing the air cleaner and ducting, the turbo outlet and oil line, the turbo, disconnecting the sensors on the intake manifold and the manifold with the EGR cooler.

The oil cooler is simple to access once the intake manifold is off. Cleaning all the parts before installation is messy due to the enormous amount of carbon soot.

Lastly, consider this. If you had simply noticed the coolant system leaking or beginning to overheat and shut down quickly, you can replace these items and you are good to go.

However, if you experienced hydro lock or engine overheating for any length of time or to any high degree… it is possible that the cylinder head gaskets have been compromised and replacing the coolers will not solve the problem in its entirety.

Blown head gaskets run the possibility of cracked valve seats in the heads. Be prepared for a large bill, should this be the case. Unfortunately, the only way to test the head gaskets is to replace the coolers first.


English: Line art drawing of a diesel engine.

English: Line art drawing of a diesel engine. (Photo credit: Wikipedia)

Ford introduced the world to its powerful 7.3L Diesel engine in 1994 and for the next decade no truck would come close to matching the Power Stroke’s popularity. The Power Stroke ended production in 2003 but features such as the electronically controlled HEUI injector system have contributed to a legacy of over 2 million vehicles still on the road. 

ITEC Lays the Groundwork 

In 1987 the International Truck and Engine Corporation (ITEC) was contacted by Ford to manufacture a heavy-duty diesel engine for the F-250 and F-350 model trucks. The bore of the 6.9L engine was increased to 4.11 inches, giving birth to the 7.3L IDI diesel engine. The engine performed respectably and would remain in use until mid-1994 when Ford changed from indirect injection to direct injection in the legendary 7.3L Power Stroke diesel engine

The 7.3L Power Stroke Introduces Direct Injection 

Naturally aspirated engines such as the IDI are preferred by many drivers because of concerns that turbocharging puts additional strain on engine that reduces its lifespan. However the 1994 edition of the 7.3L Power Stroke has proven to have longevity surpassing any similar engine, consistently lasting for 350,000+ miles. The Power Stroke utilizes a more efficient direct injection system to inject the fuel charge directly into the combustion chamber. 

Direct Injection Through the HEUI System 

Direction injection in the power stroke is offered through the Hydraulically Actuated Electronically Controlled Unit Injector. Each of the 8 engine chambers has its own 90cc shot fuel injector which require the use of two electronically-controlled oil pumps. The pumps use two high-pressure rails to increase fuel pressure at the injectors. Supercharged, direct injection into the combustion chamber allowed the new 7.3L diesel engine to increase available horsepower from 185 horsepower in the naturally aspirated, indirectly injected IDI to an impressive 275 HP and 165 lb-feet more torque in the 7.3L V8 Power Stroke diesel engine. 

An Engine Built to Last 

The 7.3L boasted performance unmatched by any other diesel engine offered on the market at the time, which is why over 2 million remain on the road, even a decade after production ended. Efficient direct injection made for a hugely popular and powerful truck engine which could last through heavy use and extreme conditions and became an industry standard for durable engines. 


Fuel Injection

Fuel Injection (Photo credit: J Mark Dodds [a shadow of my future self])

Introduced in 1994, the 7.3-liter Power Stroke engine uses an injector drive module.

Unlike gasoline engines, diesel engines rely on heat from compression to ignite the air fuel mixture. This high compression requires equally high injection pressures.

Older Ford diesels used a hydraulic injection system. Through that system, fuel pressurized, causing the injection pump to trigger the injector. The problem with the hydraulic injection system was that air entering the fuel lines would often disable the injectors, or hamper their operation significantly.

The 7.3-liter Power Stroke operates with fuel being supplied to the injectors through fuel rails inside the cylinder heads, as well as high pressure engine oil. A computer determines when a cylinder should fire, and then signals the Injector Driver Module, which sends a pulse-width modulated signal to the injector solenoid. The solenoid then opens a poppet valve, thereby allowing high pressure oil to flow into the intensifier piston. The piston is forced down, which pressurizes fuel inside the injector. When fuel pressure in the injector reaches roughly 2,700 psi, the injector pintle rises and fuel is injected into the cylinder.

To replace the driver, access it through the driver side fender by removing the inner fender lining. Take care to ensure connections are free of corrosion before installation.

EGR Cooler for 6.4L Overview

egr cooler

With the new EPA regulations requiring an EGR cooler installation into all diesel vehicles, it’s important to A) know what an EGR cooler is, and B) know how it works and how to keep it working. Let’s take a 6.4L engine; a pretty good sized diesel engine at that. The EGR circuit that houses the EGR would also have the cooler running in the same circuit.

As the EGR pulls the exhaust emissions back into the engine through itself, the emissions have to go through the cooler first. The cooler does exactly as its name implies; it cools. The cooled exhaust acts as an additional way to cool the combustion chambers inside the engine, producing less exhaust because the efforts of the engine are less from being cooled. So the process continues until the truck is turned off ad started again the next day.

In a 6.4L powerstroke engine, the engine is already working overtime. The recirculated and cooled exhaust comes back through and slows down the strokes of the engine, even when the engine is still working to keep the truck up to the current speed. The EGR cooler never fully shuts off, but continues to work hard to keep the combustion chambers from exploding because of excess heat. It’s important that a diesel combustion engine doesn’t overheat because then it produces too much NOx emissions for the EGR to filter.

High Pressure Oil Pumps Keep Powerstroke Engines Running in High Performance Vehicles

When you hear the word “powerstroke,” you might think it belongs to the newest heavy metal band. But car enthusiasts know that a powerstroke is a type of diesel engine in a lot of high performance vehicles such as trucks, vans, SUVs, and commercial vehicles. The name powerstroke is most often associated with those engines in Ford vehicles.

Most engines need oil for lubrication over parts and for cooling down the engine so that it continues to operate efficiently. This engine oil is under pressure as it moves over rotating bearings and camshafts, as well as sliding pistons inside the engine. The pressure oil lubricates the machinery so that it can move properly. For oil to circulate through the engine, oil pumps are used to maintain the correct amount of pressure to oil so that it constantly flows through engine machinery.

High Pressure Oil Pumps Different engines require different amounts of oil and different types of pressure. For typical powerstroke engines, they require high pressure oil pumps. These high pressure pumps generate the necessary pressure that is required for the fuel injectors to fire. The larger the injector, the more pressure the oil must have for the engine, and the higher pressure pump that is needed for the right oil circulation.

Problems With Oil Pressure When you have problems with the oil pressure, the powerstroke engine can become seriously damaged. Most engine problems are the result of debris in the oil that clogs up the oil pumps filter screen. When debris clogs the screen, there is lower pressure running through the engine machinery. Changing the oil and replacing the oil filter can prevent the amount of debris circulating through the engine.

Another major problem can involve basic wear and tear to the bearings and seals. When bearings and seals wear out, more oil will pass through the engine to result in lower pressure from the oil pump. To fix this problem, the bearings need to be replaced.

High Pressure Oil Pumps And Powerstroke Engines Giving the Performance Your Vehicle Needs Powerstroke engines require high pressure oil pumps for a efficient running engine. Without these pumps, vehicles with powerstroke engines would experience problems that lead to engine damage and a vehicle that runs poorly, if at all.

Changing a High Pressure Oil Pump

Replacing or changing the high pressure oil pump in a vehicle is a lot like changing the oil itself. Most of the steps are the same until you get to replacing the HPOP. It’s not a difficult procedure and if you are do-it-yourselfer, you will save yourself a decent chunk of change.

  1. Do not change the HPOP outside. There is too much potential and too many ways for dirt to enter the engine if you do this outside. Inside your garage is much, much better.
  2. Put the parking brake on and jack up the car underneath the axles. It’s easy to see why auto manufacturers don’t want mechanics to do this with only the frame as support, especially if you’re changing the HPOP on a two ton truck. If it lets go, a car would kill you; what do you think a truck would do?
  3. Drain the oil. Yep, just like changing the oil, let it all drain out. Having an oil drain pan might be a good idea here.
  4. Locate the HPOP. It will be close to the back of the engine. In a diesel there should be one or two hoses connected to it too.
  5. Remove the mounting bolt or bolts. Again, it depends on what you’re working on; most cars will have one mounting bolt while trucks and diesels will have two. On a diesel you may have to disconnect the pump’s hoses to get to the pump.
  6. On some models you might have to remove the oil pan to get to the pump. Otherwise, you might not be able to locate the pump.
  7. Remove the pump. If the pump needs lubrication before installation or any other special instructions make sure you follow them to the letter or you’re going to have to repeat this process.
  8. Once installed, put everything else back into place. Then change the oil and refill.

That’s it; it’s a piece of cake. The process is a little more intense for diesel engines, and has a few extra steps, but the basic procedure is the same.

Clean a Diesel Fuel Injector

Cleaning a diesel fuel injector isn’t like cleaning a standard fuel injector. You can’t just dump fuel injector cleaner into the gas tank and hope for the best. (Well, you can, but if your diesel engine hasn’t been cleaned in a whle, this won’t prove very effective). A manual, take down, take apart cleaning is what a diesel fuel injection system really needs.
Purging the diesel fuel injector system is the first in several steps. You can buy a kit that will help you do this. It should come with two bottles of a cleaning fluid that really just acts as a pressurizing agent and takes most of the buildup out of the engine block.

Prop or hoist the car up to a position where you can best get underneath without injury.

Detach the fuel pump. The ignition should be turned off; never do this procedure with a diesel car or truck running. You would be surprised how many people have tried. Fuel of any kind is flammable and life and limb have been lost because the ignition was on.

After finding and differentiating the fuel supply and return valves, disconnect the attached hoses an connect the purge solution bottles that came with the kit. Have the bottles filled with the recommended amount of purge solution and turn on the car or truck.

Next, this is the moment when you will want to have the engine on, and not one second before. Give it a few minutes,then floor the gas a few times. Your brakes better be on!

Alternate the speeds at which you gas he engine. This gets the cleaner into all the nooks and crannies of the engine. Do this for about ten minutes, then turn the car or truck off.

Finally disconnect the cleaning bottles and reconnect all the hoses, valves and the fuel pump which need to be bolted back into place before the vehicle can run again. Not connecting everything correctly means the pressure inside the engine will cause the engine to stall. Restart the vehicle again and let it run for awhile to test the effectiveness a function of the cleaning process.

Brief History of the Powerstroke Engine

The early to mid ’90s saw a slight shift in the automobile market. The trucking industry would undergo a major make-over and the station wagon would be replaced as the all-American full-sized passenger vehicle. The Power Stroke engine was a design idea offered to Ford by the engine designer Navistar in 1994 to meet new demands. Navistar designed and built it with the vision to give Ford a competitive edge in the heavy-duty and light-duty truck market as well as in the growing full-sized SUV division.

The Predecessor

The 7.3L Power Stroke was first in ine for public scrutiny. It would do well as the designers would build against knocking flaws and ignition problems cited in other trucks. It weighed in at 920 pounds, offered 250 horsepower and 505 lb-ft. of torque. Because of a uniquely designed fuel injection system, the Power Stroke introduced an engine with less of a knock and a more efficient ignition process. It also featured an aerating system that provides more horsepower and lower emission gas temperature. Because of these features, it grew in popularity and boasted the support of over two million consumers worldwide by 2003.

But then it had to be replaced.

The Tech Descendants

The year 2003 saw new emissions standards that would put the well-designed 7.3L into the restricted pile. The new standards, if followed without ingenuity, would yield expensive manufacturing and reductions in horsepower. A cycle of modifications would ensue in order to maintain its efficiencies and towing ability. The 6.0L Power Stroke was birthed.

Although it was smaller in diameter than its predecessor, its enhanced technological components rendered it at 1,100 pounds. It introduced the (engine gas recirculation) EGR system to help meet the new emissions standards. The 6.0L would improve on the 7.3L horsepower and torque output, giving out 325 hp and 570 lb-ft. of torque. In the days to follow, the Power Stroke would see its line through more changes in emissions standards.

The current market product is the 6.7L Power Stroke. While it does its job as medium-duty engine, it takes on the character of the American muscle car as it has a turbo system mounted on top of the engine. It is a continuation of Ford’s commitment to excellence in green technology and power. It has a horsepower output of 400 and releases 800 lb-ft of torque. It is currently housed by the Ford Excursion, Ford Econoline vans and various commercial lines with appropriate specs for each.

The Power-Stroke Effect

Perhaps the most important aspect of the Power Stroke engine is that it introduced electronically-controlled engines into the market. Other brands would follow in suit, creating engines that were more sophisticated and offered more horsepower. The Power-Stroke effect has undergirded a slow revolution in trucking power and trucking environmental compatibility.