When diesel owners in the Midwest seek the best performance money can buy, they come to a place where some very serious horsepower is made-Scheid Diesel. It's a business that, oftentimes, is directly linked to the most successful sled pull and drag race vehicles in diesel performance, not to mention some of the hottest running street trucks around. With this kind of reputation, and with our Midwest bureau being located so close to Scheid Diesel's Effingham, Illinois, location, we knew which shop would be turning up our '02 Dodge dualie. After all, some of the most powerful trucks in the country leave Scheid's shops on a daily basis.
The 24-Valve Plan
We'd already installed a TS Performance MVP module on our 24-valve Cummins ("Smokeless Horsepower", April '09) and were ready to turn the truck into the ultimate street and tow vehicle. First and foremost, we needed to address our truck's low fuel pressure issue-a common problem on '981/2 to '02 Dodges equipped with Bosch's electronically controlled rotary VP44 fuel injection pumps. Oftentimes, a failing factory lift pump will starve the injection pump-which results in both components failing. We planned to solve this problem by installing a FASS 150 series fuel system, followed by one of Scheid's Lightning VP44 injection pumps and a set of its Lightning injectors. From there, we planned to clean up our newfound fueling with one of its Lightning turbos.
Baselines
When Scheid strapped our 24-valve to its Mustang dyno for some baseline runs with the TS Performance pressure box turned up, the results told us that fuel pressure was not only weak, it fell to 0 psi at wide-open throttle. The lack of fuel was evident in our lower horsepower and torque numbers. At 248 hp and 714 lb-ft of torque at the wheels, the truck had lost 14 hp and 11 lb-ft since our last visit.
Fass System Install
Knowing the truck's fuel tank would need to be pulled, we arrived with just over a quarter tank of fuel. And, after all the hardware and tools for the job were laid out, the technicians at Scheid began the FASS fuel system install. The FASS pump and filtration unit was marked and mounted along the driver-side framerail and the tank was pulled.
Our truck had been retrofitted with an in-tank replacement lift pump from Dodge (which bypasses the engine lift pump). This required the guys at Scheid to drill a 11/4-inch hole in the tank and install the replacement suction tube included with the FASS kit. After that, the fuel tank was reinstalled and all return and supply lines were connected-then run from the tank, through the FASS system, and up to the injection pump. At this time, Scheid's technicians also removed the factory fuel filter reservoir assembly. Then the wiring was completed, the fuel system was primed, and the truck was started. The result: fuel pressure was 16 psi at idle.
Second Dyno Run
Once strapped back on the dyno, the fuel pressure held steady at 15 psi under wide-open throttle. Now we were ready to put our newfound fuel pressure to use.
 With a fuel pressure gauge...  With a fuel pressure gauge hooked up, the Scheid technicians told us our stock fuel pressure was only around 6 psi at idle and fell to 0 psi under full throttle. This is a textbook example of what many VP44-equipped trucks experience-the ailing factory lift pump (or replacement) not supplying enough fuel to the injection pump. |  Before the Scheid technicians...  Before the Scheid technicians began installing the FASS system, all included hardware (fuel fittings, hose, hose clamps, nuts, bolts, and wiring) were laid out. The FASS 150 kit came with a Fleetguard fuel filter (PN HF6601) and water separator (PN FS1023), which can be purchased at most automotive parts stores. Also included in our kit were FASS's new rubber mounting bracket spacers for quieter operation. First, the Scheid guys drilled two 3/8-inch holes and, using the included 3/8-inch bolts and flanged nuts, mounted up the FASS system along the driver-side framerail (shown). Then they filled the fuel filter up with some diesel to ease the priming process. |  The power source (arrow) for...  The power source (arrow) for the fuel system was routed from our relay box rather than one of our batteries to avoid any corrosion issues (the ground wire was run from the driver-side negative battery cable). Also, while under the hood, the factory fuel supply line running to our injection pump was disconnected. |