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Cummins Injection System Spotter's Guide

Bosch Pumps Used By Dodge From '89 To '10

Text By Jason Thompson

For the last 21 years, Dodge has offered the proven B-series Cummins engine in its 3/4- and 1-ton pickups. However, the Bosch-built injection systems found on these straight-six diesels have varied greatly through the years.

The '89 to '93 trucks featured a mechanical-injection distributor-type pump (VE rotary) that's proven reliable but is thought to offer the least horsepower potential. For '94 to '98 Dodges, the 5.9L-powered Rams got an inline injection pump (P-pump) that's become the diesel performance equivalent of the Holley 4bbl carburetor. Stricter emissions laws brought about a solenoid-controlled, axial-piston, distributor-style pump (VP44 rotary) for '981/2 to '02 models, which suffers (perhaps unfairly) from a reputation for low-performance and poor durability. The '03-and-later trucks got a common-rail injection pump (CP3), which represented a huge breakthrough for Cummins. The CP3 pump is still used on the current Dodge trucks.

Why so many different systems? Well, how diesel fuel gets injected changes an engine's performance, maintenance, and durability potential-not to mention its personality. The following is our rundown of the four different injection systems Dodge used on its Cummins engines.

Bosch VE
Application: '89 to '93 Dodge 5.9L
How it Works:
The VE injection pump is a mechanically controlled, axial-piston rotary pump. It uses a vane-type supply pump to generate an internal pump pressure that increases with engine speed. It has a single pumping plunger, called a distributor plunger. This plunging and rotating shaft generates injection pressure and controls injection timing. Six individual delivery valves, located in the pump body, connect the pump to the injectors.

  • Injection pressure range (stock): 5,075 to 17,400 psi 1 or 10,152 psi 2
  • Power it takes to spin it: 3 to 5 hp 4
  • Amount of fuel it pumps (stock): 88 to 120 cc every 1,000 strokes 1, or 105 mm3 of fuel per stroke 2
  • Amount of fuel it is capable of supplying in modified form: 400 cc every 1,000 strokes (enough fuel for 700 to 800 hp) 3
  • Advantages: It can be fitted with many options to aid in starting, atmospheric pressure compensation, manifold pressure compensation, and temperature-controlled idle speed increase.
  • Weak link: The VE pump won't support the fuel and rpm ranges the P-pump does.

Bosch P7100 (P-Pump)
Application: '94 to '98 Dodge 5.9L
How it Works:
The mechanical inline P7100 injection pump has six plunger-and-barrel assemblies (cam lobes, plungers, barrels, and delivery valves). As the pump's camshaft rotates, the cam lobes drive the six pumping plungers up and down in their barrels. These six individual plungers provide the injection pressure, while the pump's camshaft dictates the firing order.

  • Injection pressure range (stock): 15,225 psi 2
  • Power it takes to spin it: 10 to 12 hp (needs to be tested on a 15hp electric test bench) 4
  • Amount of fuel it pumps (stock): 135 mm3 per stroke 2
  • Amount of fuel it is capable of supplying in modified form: 900 cc every 1,000 strokes (enough fuel for 1,600 to 1,800 hp) 3
  • Advantages: The P-pump is easily modified to deliver a massive amount of fuel and rpm range for perfor-mance diesel applications.
  • Weak link: These pumps are not as compact as the VE pump and have more moving parts to spin, since each engine cylinder requires its own plunger.

Bosch VP44
Application: '981/2 to '02 Dodge 5.9L
How it Works:
The VP44 is a distributor-style, solenoid-valve-controlled, radial-piston pump that is electronically regulated. Like the VE, the VP44 uses a vane pump to supply fuel to its internals, but instead of a single pumping plunger, it has three. A high-pressure solenoid valve opens and closes the pump's element chamber to control fuel metering independently of engine speed. The VP44 pump has a built-in ECU that monitors its operation and adjusts engine fueling. The VP44 requires an electric lift pump to feed it diesel from the fuel tank.

  • Injection pressure range (stock): 15,950 psi 2
  • Power it takes to spin it: 3 to 5 hp (needs to be tested on a 7hp electric test bench) 4
  • Amount of fuel it pumps (stock): 125 mm3 per stroke 2
  • Amount of fuel it is capable of supplying in modified form: 600 cc every 1,000 strokes (enough fuel for 1,100 to 1,200 hp) 3
  • Advantages: The VP44 has the advantage of electronically controlled direct-injection, which gives more precise metering of fuel delivery when compared to the VE and P-pump.
  • Weak link: Like the VE pump, the VP44 won't be able to support the rpm ranges the P-pump can. A common problem associated with the VP44 pump has nothing to do with the pump at all, but rather its lift pump. It is essential that the VP44 gets enough fuel supplied to it-or it will fail.

Bosch Common-Rail CP3
Application: '03 to '10 Dodge 5.9L and 6.7L
How it Works:
The CP3 is a radial-piston pump driven mechanically by the engine. Since the CP3 pump's only job is to create fuel pressure, it's not necessary for it to be timed with the engine's crank and camshaft position. The CP3 pump is the only Cummins injection pump Dodge has offered that does not control injection timing or fuel quantity directly. The CP3 merely provides the requisite amount of fuel to the fuel rail, and the injectors have the authority over fuel delivery.

  • Injection pressure range (stock):23,201 psi 2
  • Power it takes to spin it: 10 to 12 hp (needs to be tested on a 15hp electric test bench) 4
  • Amount of fuel it pumps (stock): 200 lph (liters per hour)2
  • Amount of fuel it is capable of supplying in modified form: 380 lph (liters per hour) 2
  • Advantages: Offers higher injection pressures and facilitates multiple injection events per power stroke. This decreases emissions and increases efficiency.
  • Weak link: Injectors are expected to do more, so they are more expensive compared to the earlier systems.

Industrial Injection
1201 South 700 West
Salt Lake City
UT  84104
Garmon's Diesel Performance
1222 High Falls Rd.
GA  30223
Scheid Diesel
4960 North 13th St
Terre Haute
IN  47805
McCormick Diesel & Brake
37922 Sierra Highway
CA  93550
38000 Hills Tech Drive
Farmington Hills
MI  48331
United Diesel Service
By Jason Thompson
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