7.3 Power Stroke Cylinder Numbers, Firing Order, Main Specs, And Problems

The 7.3 Power Stroke (Ford Powerstroke) engine was popular for producing a lot of power and getting perfect fuel economy. This legendary, heavy-duty truck engine offered greater performance specs than its predecessors, the 6.9 and 7.3 IDI. The Ford Powerstroke was even more reliable than the 6.0 Powerstroke, which succeeded it. With that in mind, we can say that it was a great achievement for the manufacturers, Navistar International and Ford. 

So, why was the 7.3 Power Stroke engine so special? What are the engine’s cylinder numbers, firing order, and main specs? Were there any issues associated with it? We have answered all these questions for you below.

7.3 Power Stroke Cylinder Numbers and Firing Order

The 7.3 Power Stroke cylinder numbers are odd on the right bank and even on the left bank. That is, the numbers on the right are 1, 3, 5, 7 and those on the left are 2, 4, 6, 8. The numbers 1 and 2 are the two cylinders in the front and that brings us to the firing order.

Well, this is the order in which the cylinders in the internal-combustion engine get sparked and fired. Accurate firing order is likely to bring about minimum vibrations in an engine system. Minimum vibration facilitates a smooth ride. That’s because when the vibrations are less, the driver and passengers won’t notice as the engine transmit them. The 7.3 Power Stroke engine firing order is 1-2-7-3-4-5-6-8.   

7.3 Power Stroke Main Specs 

The 7.3 Power Stroke turbo-diesel engine was the first of Navistar International’s production for Ford. It’s an electronically controlled and direct-injection V8 engine that powered heavy-duty commercial vehicles. The engine came with 210 horsepower, producing 425 lb-ft torque. It had 4.11 inches bore and 4.18 inches stroke, which created a displacement of 444 compression ignition (ci).

The 7.3 Power Stroke engine was simple but still quite advanced and that was one thing that made it stand out. Most of its incredible performance specs were characterized by direct fuel injection through HEUI (Hydraulic Electric Unit Injectors). These outstanding injectors are combined with high-pressure oil pumps (HPOP). Additionally, the 7.3 Power Stroke came with a more powerful turbocharger than its predecessor 7.3 IDI Power Stroke engine. 

The late models of the 7.3 Power Stroke even came with air-to-air intercoolers, which supplied more cold and dense air. That improved performance significantly. That is, the 1994 7.3 engine produced 210 hp and 425 lb-ft of torque.

However, the manufacturer made some adjustments that saw the later 7.3 models (2000 to late 2002) come out more powerful. In other words, these later models produced 275 hp and 525 lb-ft torque. They were also equipped with a 6-speed manual transmission. 

As mentioned, the 7.3 Power Stroke engine utilizes direct fuel injection unlike its predecessor the 7.3 IDI. That means that the engine system injects fuel into the combustion area directly, leading to improved horsepower with cleaner emissions. 

HPOP (High-Pressure Oil Pump)

The 7.3 Power Stroke engine utilizes an HPOP for pressurizing the fuel through the injectors. This unique oil pump is gear-driven and features a fixed-displacement design. Another performance spec we see in the 7.3 Power Stroke engine is the swashplate pump style. The swashplate helps in determining the HPOP’s oil output. Early 7.3 Power Stroke models (1994 to 1999) come with a 15-degree swash plate while later models (Mid 1995 to late 2002) use a 17-degree swashplate. For that reason, the later models provide higher oil volume, allowing them to support more performance mods easily. 

The HEUIs (Hydraulic Electric Unit Injectors) utilize oil that the HPOP supplies to activate injection processes. That happens on poppet valve opening and letting high-pressure oil go into the injectors, which eventually enhances combustion efficiency. 

A Quick Summary of the 7.3 Power Stroke Main Specs

• Engine design – The 7.3 Power Stroke is a powerful V8 turbocharged diesel engine. 
• Cylinder head – A cast-iron cylinder head with 6 head bolts in each cylinder 
• Engine weight – 920 pounds
• Engine block – Cast iron block
• Transmissions – The transmission of the 7.3 Power Stroke engine is different based on the production year. Models produced from 1994 to 1998 include the E40D, which utilized a 4-speed automatic transmission. The other models within the same period are the ZF S5-47, which came with a 5-speed manual transmission. The 7.3 Power Stroke engines produced from 1999 to late 2002 include the 4R110, which utilized a 4-speed automatic transmission. Still within the same year is the ZF S6-650, which utilized 6-speed manual transmission.   
• Compression ratio – 17.5:1
• Valvetrain – Overhead Valve (OHV) with 2 valves in each cylinder and hydraulic lifters. 
• Horsepower – Horsepower in the 7.3 Power Stroke engine varies depending on the year of production. As mentioned, engines produced from 1994 to 1995 produced 210 hp. The 7.3 Power Stroke released in 1996 gave out 215 hp while the engines produced in 1997 to 1998 produced 225 horsepower. Later models of the 7.3 Power Stroke continued to improve in terms of power output. The models produced from 1999 to 2000 offered 235 horsepower. And the ones produced from the year 2001 to late 2002 with automatic transmission and produced 250 hp. Models produced in the same year with manual transmission produced 275 horsepower. 
• Torque – Like the horsepower, the 7.3 Power Stroke engine’s torque also varies based on the year of production. The first engine models (1994-1995) provided 425 lb-ft of torque while the subsequent models produced in the year 1196 to 1998 gave out 450 lb-ft of torque. Models produced from 1999 to 2000 produced 500 lb-ft of torque while those produced in 2001 to late 2002 with automatic transmission produced 505 lb-ft of torque. The 7.3 Power Stroke models produced from 2001 to late 2002 with manual transmission provided 525 lb-ft of torque.  
• Fuel tank capacity – 29 gallons for the Short Box and 38 gallons for the Long Box. 
• Engine coolant capacity – 31 liters
• Oil capacity – 14.2 liters
• Turbocharger – Models produced from 1994 to 1997 came with Garrett TP38 Fixed Geometry turbo. Those produced from 1999 to late 2002 have Garrett GTP38 Waste gated style of the turbo. 
• Fuel Injection – Direct injection /w new hydraulic, HEUI injectors. 

7.3 Power Stroke Problems

The Ford Powerstroke was a powerful and reliable engine. However, like any other great engine, the 7.3 Power Stroke too had its set of problems that developed over time. We have listed these issues below:

1. Camshaft Position Sensor (CPS) Failure 

CPS is an electronic device designed to monitor the rotational speed or position of the crankshaft. The CPS failure was one common problem in the Ford Powerstroke. This issue caused a no-start condition or even a stop while running.

2. Leaking Fuel

Another problem that the 7.3 Power Stroke engine has is the leaking fuel. Why does this happen? Well, the fuel filter (fuel bowl) sometimes develops cracks, through which fuel leaks. Additionally, the heating element in the filter housing can short out and blow a fuse. And when that happens, the engine will stall during idle and won’t start. 

3. Turbo up-pipe leaks

This is another common problem in the 7.3 Power Stroke engine. The up-pipes are important components of the exhaust system. They connect the exhaust manifold to the turbo. Over time, these pipes can crack due to the contraction and expansion caused by the flow of the exhaust gasses. When that happens, the up-pipes begin to leak from several different points, including the joints. 

The leaking pipes cause the 7.3 Power Stroke engine to lose power or boost. What’s more, it increases the temperature of the exhaust gases. 

4. Exhaust Back-Pressure Valve (EBPV)

The EBPV is another significant failure point for the 7.3 Power Stroke engine. This valve is prone to closing when cold. It then gets stuck and makes the exhaust generate a lot of noise, which is quite annoying for many people.  

5. Under Valve Cover Harness (UVCH)

The UVCH sometimes disconnects with either the fuel injectors or glow plugs. That causes the engine to experience rough starts or even misfire based on the production year. The fuel injectors are used to distribute fuel evenly into the engine through their atomizing nozzles. They do that with the help of electronically controlled valves. That ensures that the engine is efficient enough thanks to the optimum combustion. 

Glow plugs are heating elements designed to warm the diesel and air in the 7.3 Power Stroke diesel engines. That also leads to effective combustion and efficient starting of the engine. It’s important to note that most of these problems were electrical-related, which are associated with improper electrical connections. 

The production of the 7.3 Power Stroke ceased in late 2002, and the 6.0 Power Stroke took its position. That’s because it was unable to meet the noise regulations in California. But despite all these problems, the 7.3 Power Stroke remains the best engine that Navistar International ever produced. 

Final Thoughts

The 7.3 Power Stroke is an incredible engine produced from 1994 to late 2002. The V8 diesel engine was powerful and used to power heavy-duty commercial vehicles. Nevertheless, it had issues like fuel leaks, CPS failure, and turbo up-pipes leaks. Despite all these, the 7.3 Power Stroke is still a legendary engine with outstanding performance specs that Navistar International ever made.