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  • P-pump performance with The Adjuster by Attitude Performance Products

P-pump performance with The Adjuster by Attitude Performance Products

On-the-Fly Fueling Changes Made Easy for P-Pump–Equipped ’94-to-’98 Dodge Rams

John Lehenbauer
Apr 18, 2017
Photographers: Sean Haggai, John Lehenbauer
Historically, increasing a 12-valve 5.9L Cummins engine’s performance with only a Bosch P7100 high-pressure injection pump (P-pump) required modifying the pump’s air-fuel control and adjusting its fuel plate.
Photo 2/28   |   The 12-valve, 5.9L Cummins engine in Sean Haggai’s ’96 Dodge Ram 3500 is still running strong after more than 20 years of use. The Adjuster by Attitude Performance Products will give Sean more control over the Bosch P7100 injection pump (P-pump), which can equate to an increase in power, fuel economy, and boost, while lowering EGT.
While making the right tweaks helps increase fuel delivery to the engine, one of the drawbacks to these changes is that the new settings are semi-permanent. So, if the fuel mixture is too rich or lean for the application, there is no way to make adjustments without further tinkering with the pump. The process can be a continual guessing game, but that is where the Adjuster by Attitude Performance Products comes in handy.
The Adjuster allows the driver to manually modify the fuel-injection strategy from inside the truck. A dash-mounted control knob provides the ability to precisely tune a P-pump for optimal economy to maximum performance without having to move from the driver seat. The device is said to contribute a number of benefits, like controlling EGT, increased boost, and improved economy and power, while helping to decrease excessive exhaust smoke.
Photo 3/28   |   Here is a look at the Adjuster’s contents. The kit includes all the parts, fasteners, and such necessary for do-it-yourself installation.
Adjustability comes by replacing the stock fuel plate and AFC arm with the Adjuster’s housing plate (with adjustable arm) and longer AFC arm, which are designed for full fuel advance. The plate’s adjustable arm operates via a cable-actuated threaded rod in the housing. A knob on the in-cab controller rotates the cable through 16 settings. By retaining the AFC housing, factory boost advance is maintained for better driveability. If a bit more power is desired, an optional control-rod plug can be installed in the pump housing to further enhance fuel tuning. The plug allows the control rod to travel an additional 3mm further than stock (21mm total), which results in a power increase.
We located a daily driven ’96 Dodge Ram 3500 with a P7100 injection pump that is a perfect candidate for the Adjuster. The 12-valve Cummins under the hood has been modified to make more power. The original fuel plate is ground down (shaved) for increased fueling, and the turbocharger wastegate is blocked off to increase boost. A noticeable, negative side effect seen from the DIY fuel-plate modification is that the engine generates black smoke on acceleration.
With the Adjuster in tow, we made our way to Solvang, California, where Jay Storey at Storey Motors helped with the installation. Read on through the photos and captions that highlight the process.
Photo 4/28   |   Jay Storey of Storey Motors removes the air-intake horn in order to reach the P-pump and hard lines.
Photo 5/28   |   Adjuster Attitude Performance Products Injection Pump Hard Lines
Photo 6/28   |   With the horn removed, Jay loosens up the fittings at the pump and on the injectors and then removes those plumbing components.
Photo 7/28   |   Adjuster Attitude Performance Products Wrench Hardlines Fitting Injectors
Photo 8/28   |   Adjuster Attitude Performance Products Hardline Removal
Photo 9/28   |   Adjuster Attitude Performance Products Afc Removal
Photo 10/28   |   After removing the AFC housing, Jay inspects it and then extracts the shaft and the stock arm, which is replaced with the new, longer arm.
Photo 11/28   |   Adjuster Attitude Performance Products Afc Shaft Removal
Photo 12/28   |   Adjuster Attitude Performance Products Afc Arm Shaft Install
Photo 13/28   |   The fuel plate is removed in order to install the Adjuster’s housing.
Photo 14/28   |   The arm in the housing adjusts back and forth along the threaded rod to advance and retard the fuel rail. The tapered end of the plate points toward cab and attaches to the activation cable.
Photo 15/28   |   Jay positions the Adjuster with the O-ring down, installs the AFC, and secures the entire assembly with the supplied M6 Allen-head screws.
Photo 16/28   |   Adjuster Attitude Performance Products Afc Install Adjuster
Photo 17/28   |   Adjuster Attitude Performance Products Afc Adjuster Finished
Photo 18/28   |   Once the AFC and Adjuster are bolted down, the hard lines and air-intake horn are reinstalled.
Photo 19/28   |   Adjuster Attitude Performance Products Intake Air Horn
Photo 20/28   |   The adjustment cable must be routed smoothly through the firewall and behind the dash. Selecting a good spot for drilling the hole for this is important.
Photo 21/28   |   Jay passes the cable through the firewall.
Photo 22/28   |   Adjuster Attitude Performance Products Cable Floorboard Under Dash
Photo 23/28   |   The in-cab controller is only 3 inches long and has an easy-to-use knob. Sixteen adjustment positions are marked on the controller’s housing.
Photo 24/28   |   Once the cable is routed, mounting the controller in a convenient location is the next step. Sean decided to place the controller in the dash panel, just below the instrument cluster. The hardest part of assembling the cable and controller is finding “0,” which is the point where the housing’s adjustment and the controller’s knob are correctly synchronized.
Photo 25/28   |   Adjuster Attitude Performance Products Dash Controller
Photo 26/28   |   Adjuster Attitude Performance Products Controller Mounted Dash
Photo 27/28   |   The Adjuster’s in-cab controller definitely makes changing a P-pump’s injection settings a breeze. Dialing-in improved fuel economy or higher performance is just a knob twist away.
Photo 28/28   |   An AutoMeter pyrometer gauge makes it easy to see any changes in exhaust gas temperature when using the Adjuster by Attitude Performance Products.

New Attitude

Our Adjuster installation was smooth and straightforward, and the helpful people at Attitude Performance Products eagerly fielded any questions that arose about the installation process or using the device to make adjustments.
When driving our ’06 Dodge Ram 3500 truck with the Adjuster installed, there is definitely a noticeable difference in the 5.9L Cummins engine’s performance. The first improvement is a slight seat-of-the-pants power increase when the controller’s knob is cranked all the way to the 16th position for max fueling. Even more noticeable is the lack of smoke when the accelerator pedal is matted (even at that 16th position). Using AutoMeter Competition Instruments pyrometer and boost gauges, the already-bumped-up 30 psi of boost did not increase during our test. However, the turbocharger did reach peak boost quicker, which improved the truck’s acceleration.
After using the Adjuster for two months, Sean says, “The ability to refine fuel settings on the highway is a great asset for increasing fuel mileage. If you are going from a stock fuel plate to the Adjuster, the gains will probably seem huge.”
Storey Motors
(805) 697-7903

Sources

Attitude Performance Products
855-781-6100
attitudeperformanceproducts.com
AutoMeter Competition Instruments
866-248-6356
autometer.com

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