Dodge Ram Diesel VP44 Injection Pump Fix
How to Replace the '98 1/2-to-'02 Dodge Ram's Problematic VP44 Injection Pump
There are many advantages that make 5.9L Cummins-powered '98 1/2 to '02 Dodge Rams very desirable trucks—especially from an engine standpoint. First, the engines don't have the killer dowel pin problems that plagued 5.9Ls of the '94 to '98 models. And engines in '98 1/2 to '02 trucks are also easily upgraded for increased performance, thanks to inexpensive fuel injectors and electronically manipulated fuel and timing trims. It's not uncommon for rigs of this later vintage to put 400 to 600 hp on the ground. Despite the favorable attributes, the 5.9L Cummins in this generation uses a VP44 injection pump (the weak link, if you will) known for lasting anywhere between 100,000 to 150,000 miles before it fails completely or throws OBD-II "death codes" at the owner for quite some time (P0216 is a popular one) before conking out.
The bottom line? Failure among VP44s is quite common. If a truck has 250,000 to 300,000 miles, it could be on its third or fourth injection pump. This VP44 problem is so mainstream that companies have started building injection pump pullers for those who are looking to tackle the job. To see how a VP44 removal and install is done, we followed Matt Ray and mechanic Jared Estrada at Siskiyou Diesel Performacnce, a Central Point, Oregon, shop that averages two or three VP44 replacements per month.
The first step in replacing the factory VP44 pump is the removal of the intake horn, which is accomplished by loosening the manifold bolts and the hose clamp on the intake boot. The batteries are also disconnected to avoid any shorts.
Next, the pump's cover is removed, along with a small electronic plug.
Siskiyou Diesel Performance technician Jared Estrada then removes the plug to the electronic portion of the VP44. Note that this plug has a sliding portion that's used to lock and unlock it from the pump port.
With the electronics disconnected, both the banjo bolt feed line and injection-pump-to-injector lines are loosened at the pump itself.
Since the pump needs to be moved around quite a bit for removal and installation, the injector lines are also loosened at the injectors and removed. When performing this task, keep the clamps that hold the individual injector lines together attached (arrows), so the lines go back into the truck smoothly.
With the lines, plug, and cover removed, the pump itself is loosened from the case, by removing four bolts (two on top, and two underneath the pump).
With the pump loose, the pump-gear nut is removed. It's helpful to have a barring tool or to hold the harmonic balancer to prevent the engine from turning.
A puller is needed to remove the gear from the pump shaft. However, before it can be extracted, the engine must be slowly rotated until the pump keyway faces up to ensure a broken or loose keyway won't fall into the gearcase when the pump is removed.
The final step for removing the VP44 involves using Industrial Injection's new pump-removal tool.
With the fuel lines and intake horn removed and the pump gear pressed off the shaft, it's finally time for the tired stock VP44 to be removed.
A new injection pump from Industrial Injection replaces the factory VP44.
Siskiyou Diesel's Matt Ray handled the delicate-but-muscle-intensive job of working the pump shaft and keyway back into the old pump gear.
Once the pump is bolted back onto the gearcase, it's time to secure the drive gear. With Matt holding the alternator, Jared torques the nut on the gear to the recommended 125 ft-lb.
The injection lines go back on after the new pump is installed. Jared starts by laying the lines out, then tightens them down at each injector first.
Connecting lines to the VP44 comes next, followed by securing the lines to the engine by their hold-downs.
The final two steps involve connecting the fuel-feed lines to the pump, then the plug for the electronics.
Since diesels (especially if they're modified) operate with large amounts of boost pressure, using the stock intake gasket is never a good idea. Before reinstalling the intake horn (remember to remove any rags from the intake), a new gasket is set in place.
With the new, Industrial Injection VP44 injection pump installed, the pump cover (which includes a small electrical plug) is returned to its original position.
Before starting the engine, it's common to loosen one or two injector lines to bleed any excess air out of the system while the engine is cranking over.