7.3 Power Stroke Loses Power While Driving – What’s Wrong?

For its large trucks and vans, Ford used a 7.3 Power Stroke diesel engine from 1994 to 2003. This was a legendary engine and thousands of units were sold with Ford cars in the US. Now, still, some engines are on the go and are helping businesses and farms all over the country. It's a very reliable and powe3rful engine with immense torque to tow and haul weights.

Key features and my opinion about the engine

• Production years:1994-2003
• Average lifespan of 7.3 Power Stroke:380,000-450,000 miles
• Fuel supply type:direct injection
• Power range:250-275 hp
• Fuel efficiency:bad
• Engine block material:cast iron
• Engine reliability score:high
• The most common problems:electronics problems, wiring issues, pretty bad fuel economy.

How does it feel when your 7.3 Power Stroke loses power?

Well, there are two ways for this engine to lose some power: sharp and gradual. The gradual power loss will occur in nearly any engine because of the natural tear and wear process. Some parts will get defects and problems, the efficiency will get reduced over time. But this happens gradually over years and you will not notice this much. There is nothing you can do about it but the proper regular maintenance of your engine.

We will be talking about a sharp change in the behavior of your engine. This sharp loss of power can be a reason to worry because it will show one or a couple of problems. And this sharp loss of power needs proper investigation and diagnostics.

Here are some of the most obvious symptoms:

1. You press the acceleration pedal and the vehicle won't accelerate as you expect it to. This means the engine has no proper power for quick acceleration.
2. You try towing some heavy trailer with your truck but for this, you need to press the acceleration pedal to the metal to get your truck going at least slowly.
3. Your vehicle loses speed when going up the hill. The transmission will also start changing gears and the vehicle may go on high RPM with jerking all the time.
4. The vehicle accelerates poorly and once you press the pedal harder, it stalls or coughs instead of accelerating properly.
5. At some point, your vehicle jerks and start going faster. But then, after idling for a while near a traffic light, everything repeats and the car doesn't want to accelerate.
6. You see a lot of black smoke from the tailpipe because the diesel you are sending to the combustion chambers isn't burnt properly and gets to the exhaust.
7. Fuel consumption goes up because the engine tries to compensate for its power loss and starts burning more and more fuel.

All these factors may happen all together or in some combinations. Usually, you will not experience all seven symptoms at once. They will change each other and combine with each other to spoil your mood at different times. But one thing will be clear - you will need to repair the vehicle and not wait until something happens and it starts working well.

Well, there are still some chances that the problem occurred because of side factors such as the quality of diesel fuel. But in most cases, it will be all about the condition of the important technical units in the vehicle. Which units? Let's see.

What can cause a sharp power loss when driving a 7.3 Power Stoke equipped car?

The reasons can be different. One of them, for example, is total engine damage which means you will need to choose between an unpredictably expensive repair or an engine swap. If all of the symptoms listed above are present in your engine, you should be getting ready for this. But usually, this may happen in two cases: with poor regular maintenance and on extremely high mileage.

After 250,000 miles on the clock, this engine may start showing some of these issues. But it doesn't necessarily mean that you will have to just throw the engine away and buy a new one. Sometimes, the problem is much cheaper to locate and repair.

For example, we can think of these problems:

1. High-pressure fuel pump. Diesel engines use high-pressure pumps. This means that once these pumps fail to deliver needed pressure, the engine starts glitching like crazy. Check the pump and the diesel fuel pressure in the system.
2. Fuel injectors. They may stop spraying diesel fuel correctly and just pour it into the chamber which will result in poor ignition and inefficient fuel use. This means you will have to repair or replace the injectors which are not that cheap.
3. One of the engine sensors. Checking the sensors is not hard - you can use computer diagnostics for this. Even some simple fault code reader will assist in solving this problem at no cost.
4. Turbocharger failure. The 7.3 Power Stroke engine is a turbocharged diesel unit, so the turbo failure is one of the most obvious reasons the problem could occur. Checking the turbocharger is one of the first things you should do.
5. Air intake problems. The power is formed when air is mixed with fuel and is sent to combustion chambers. If there is not enough air in the system, the engine will fail to deliver the needed power.
6. Transmission problems. Very often, the problem of power loss is not connected to the engine. The transmission is to blame for not sending this power to the wheels.
7. Clogged filters. You will be a lucky person if you find out that the sudden power loss in your Power Stroke diesel engine is caused by just dirty filters. Look at (or better just change) those air and fuel filters and think whether they need replacement.

So many things can go wrong with your 7.3 Power Stroke. But in most cases, it's not that hard to locate the actual problem. Repairing this engine can still be a problem because it's quite old and you will not find decent parts for it. Also, few mechanics will want to dog in this engine and locate problems because all the electronics and other modules are old and can fail.

So, the good news: you can easily locate the problem and repair it unless it's about the fatal engine wear. Bad news: it's not that easy to repair this engine. Once you start changing and replacing something, you will need to continue until you change pretty much everything. Just because the 7.3 Power Stroke is quite an old engine.

Avoiding problems of power loss with your 7.3 Power Stroke diesel

To avoid problems with this engine, you will have to think about regular maintenance. Remember about all the requirements of the manufacturer. Maybe, changing oil and filters even more often than recommended will be a good idea for old and high-mileage engines.

You will be able to save your engine if you don't overload it when towing trailers. Every vehicle has its own towing capacity - remember about it and never try towing more than allowed.

Also, here are some of the most important recommendations:

• always pay attention even to small troubles and changes in the way your 7.3 Power Stroke works;
• never use bad fuel - diesel should be clean and with optimal characteristics to let the engine work properly;
• don't think about turbocharger modifications or any other tuning options - this will kill your Power Stroke immediately;
• pay attention to high-mileage engines and be careful with them, they are very demanding and tender;
• buy high-quality parts and materials, never try using cheap oil because it will kill the turbo and other parts of your engine;
• don't rev up the engine too much, the unit doesn't like revving up at all and it works better at low RPMs.

These are the simple requirements that will help you avoid many problems with your 7.3 Power Stroke engine. It doesn't mean you will not have any issues at all. Once, the engine will still be broken and will need replacement. But the mileage of the 7.3-liter diesel engine is over 350,000 miles, so it won't be very soon.

Final words

What we love about the 7.3 Power Stroke diesel engines, they are really simple for diagnostics and repair. These engines are wonderful, they can live long and tow everything you need. They aren't afraid of harsh conditions or heavy trailers. But of course, they still have some disadvantages and possible issues.

If you happen to experience sudden power loss in your 7.3 Power Stroke, you should just check the systems of the engine one by one and you will locate the problem even without professional diagnostics.