It has long been debated between the GM camp, the Dodge tent, and the Blue Oval boys, what really brought us to the level of diesel technology we currently enjoy. Each has made some real contributions, but the Ford Team has long held that the Power Stroke started the diesel market revolution, just as the American buyer was looking for more towing power in the mid-1990s.

While the diesel engine has been around for a while in the light truck market, even with a turbocharger, it was not until Ford and engine builder/supplier International offered up the first computer-controlled engine in 1994 that the Power Stroke revolution was truly born. While there were many engines available, the one that is generally considered to be the most durable was the 7.3-liter. With the initial computer-controlled injection feeding the 17.5:1 compression of the 7.3-liter, the 445 cubic inches were able to pump out 215 hp and 425 lb-ft torque that fit the need for more power.

The concept, design and implementation were so well received, just three years later, International had increased delivery of the engines by almost 250 percent, with a reported total of 206, 000 engines in 1998. It was the next year, 1999 that the Blue Oval put its stamp on the all-new Super Duty F-series truck that offered more than just luxury driver upgrades. For those buyers in need of even more power, an air-to-air intercooler was offered on the engine that was pumping out 235 hp and 500 lb-ft of torque off the showroom floor. By 2002, the 7.3 was at 275 hp and 525 lb-ft torque, with the aftermarket making it well known that with some bolt-ons, 300 horses could be easily found under the big blue oval with a Power Stroke that could have over 600 lb-ft of torque! Even though this proved to be the last of the 2-valve designs, the 7.3L lives on with an extended life and a resale value like no other on the market.

Along with being one of the most durable diesel motors, the 7.3-liter is also becoming one of the most sought after by diesel performance enthusiasts. There are even a handful of 7.3-liter specialists that have learned the tricks for tuning and making big power. One such business is Diesel Innovations of Houston, Texas. While the business may be keeping diesel engines running at peak performance, the team, led by owner David Lott, have also put together some fuel system upgrades for the 7.3 that not only improve throttle performance, but also have shown improvements in fuel mileage, and helped reduce engine wear and tear.

One such kit developed by DI is called the Fuel Tank Sending Unit and Pre-Fuel Pump Modification Kit which is used to minimize any air leaks into the fuel system, as well as maximize the fuel flow process that may be used to improve other aspects of the overall performance of the 7.3-liter engine. One of the more troublesome items with any diesel is eliminating air in the fuel system, such as at the factory quick connects on the fuel system, which can cause damage to injectors as well as hurt the performance of the truck. DI’s kit provides an improvement in the elimination of air in the fuel system that will improve fuel economy, provide a quieter running engine, as well as improved throttle response, according to David. Installation of the kit is also a great place to start when upgrading the fuel system for more power, including the installation of larger injectors and a more efficient, high-pressure fuel pump.

Next month, we’ll take the Diesel Innovations 7.3-liter fuel system upgrades to the next level with the installation of a bolt-on regulator bypass kit.

SOURCE Diesel Innovations Performance 10541 FM 1960 West #101 Houston, TX 77070 (713) 984-9441 www.DI Performance.com

1. Blue Oval purists insist the 7.3-liter Power Stroke was the best one ever produced. With some simple fuel system tweaks, the 7.3-liter can make even more power and become more efficient.	2. DI Performance of Houston, Texas, has developed a Fuel Tank Sending Unit and Pre-Fuel Pump Modification Kit” designed to minimize air leaks and provide better fuel delivery.	3. One of the more troublesome items with any diesel is getting air into the fuel system, such as at the factory quick connects on the fuel system, which can cause damage to injectors as well as hurt the performance of the truck.
4. The hardest part of the installation of this kit is getting the fuel tank down without damaging the fuel-sending unit, so do not use a floor jack under the middle of the tank or the fuel-sending unit could be damaged. Run as much fuel out as possible, and get some help where you need it. From underneath the truck, disconnect the fuel filler hose from the neck tube (body end) that leads to the tank, as well as the vent hose going to the tank by removing the hose clamps so that the ends will follow the tank as it is being lowered.	5. Inside the driver side framerail, cut the fuel line that feeds the tank — if it is a 1999 or 2000 year model, use a tubing cutter and either block the line or “crimp” the line. On a 2001 or 2002 year model, cut the hose at the framerail and block.	6. With the fuel tank properly supported, remove a pair of 13mm bolts from the tank strap frame connections, as this will allow the tank straps to swing down and back out of the way to allow for the tank to be lowered.
7. Special note: On the front frame mount for the driver side the leaf spring perch, up inside the U-shape mount is where the bolt is located, out of sight, but reachable.	8. This is an example of what you are trying to disconnect as you slightly lower the tank — the vent hose, the electrical connection for the sending unit, as well as the fuel feed line and the return lines.	9. Slightly lower the tank very slowly, being careful to keep it balanced while reaching up and over the top of the tank to remove the vent line and the electrical connection for the sending unit as shown in the example.
10. Once these are disconnected, slowly lower the tank making sure that the fuel filler hose and vent line do not hang, which could cause the tank to tilt unexpectedly causing a shift in the fuel supply and potential spillage.	11. With the fuel tank on a stable surface, remove the large black retaining nut on the top of the fuel tank by using a piece of wood and a mallet to “knock” the nut loose and then complete the removal. Do not use a sharp edge to start the retaining nut or it may cause damage, and be sure to save the round gasket for re-installation.	12. A word of caution: The fuel-sending unit is easily bent, and DI says Ford does not sell individual parts for it, so a damaged unit will have to be replaced completely. With the retaining nut removed, the gasket saved for re-installation; gently remove the fuel-sending unit by tilting the unit forward and lifting the unit out onto a stable surface.

13. With the unit lying flat, measure, and note for future reference, the distance from the bottom of the pick-up tube to the edge of the flange. Factory length should be approximately 15 1/4-inchs for a fuel tank on a long bed, and 13 3/4-inch for a short bed fuel tank.	14. Cut the two metal band clamps on the rubber hose that connects the white mixing valve to the sender and gently twist off the 3/8-inch steel line, then remove the rubber hose from the sender unit.	15. Remove the black rubber pickup foot from the white mixing valve by loosening the hose clamp from around the top of the pickup foot and then separate the two parts.
16. With the black pickup foot on a stable surface, gently remove the metal screen filter from the center of the foot before proceeding.	17. Using a 3/8-inch drill bit, drill out the center of the black foot to remove any obstructions including the soft step down lip inside the tube tunnel.	18. Insert the supplied 3/8-inch tube into the black pickup tube so it extends past the check valve on the side of the black pickup boot that was drilled through in the previous steps, attaching with a hose clamp, and then insert the other end of the supplied 3/8-inch tube into the compression fitting on the existing 3/8-inch tube of the sending unit with a snug fit, but DO NOT tighten the nut yet.
19. Attach and tighten the supplied 3/8-inch compression union fitting to the existing 3/8-inch line of the sending unit putting the entire modified unit back together.	20. With the unit lying on a flat surface, once again measure the overall length and compare to the previous measurement of the original sending unit. If it is too long, cut the new tubing to the correct length. DO NOT CUT THE TUBE SHORT or the check valve in the side of the tube of the black boot may suck air into the system - make sure the supplied tubing remains past the check valve in the foot to complete the block.	21. Make sure that the fuel tank retaining nut gasket is back in place before beginning to place the modified sending unit back in the tank, and make sure all clamps and compression fittings have been tightened.
22. To reinstall the modified unit back into the fuel tank, reverse the tilting motion used for removing the factory sending unit from the tank, making sure the orientation arrows on top of the tank match the hole on top of the tank once the unit is reinstalled.	23. Use the supplied diesel proof rubber hose to replace the factory unit that was cut at the framerails during the fuel tank removal process, securing with the supplied hose clamps, thus removing the quick connect type of connections from the tank connections. Re-install the fuel tank in a reverse order of removal, making sure all hoses clear.	24. At the fuel pump, located on the inside of the driver framerail, near the cab front door area, locate the electric fuel pump and remove the hose that connects the fuel line from the fuel tank. NOTE: on 2001 and 2002, push the blue button on the blue/black quick disconnect, while on a 1999 and 2000, use a fuel line disconnect tool.

25. On the framerail fuel line from the fuel tank leading to the fuel pump, remove the rubber hose from the metal fuel line tubing from the fuel tank being CAREFUL not to get drenched in fuel.

26. Use the supplied rubber hose and hose clamps to install the supplied in-line fuel filter — depending on the filter, either make sure the IN points toward the fuel tank and OUT towards the fuel pump and engine — or, make sure the ARROW on the filter indicates that the fuel will flow from the tank to the fuel pump in route to the engine.

27. The completed inline filter system should look like this, with the in-line fuel filter just before the electric fuel pump, located on the inside of the driver’s side framerail where it can be protected.