Attention: TDR Forum Junkies 
Pages that can be found on the net about the VP but the search engine is once again showing us that it can be a friend and a thread like this can be useful on the tdr.
I give credit to the Dodge ram.org site for the folowing page:
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An article appearing in the March 2000 issue of Petersons 4Wheel & Off Road quoted Dr. Diesel saying that the VP44 injector pump used on 24 Valve ISB Dodge diesel trucks was UNRELIABLE compared to the 12 valve engine's P7100 injector pump.
Curious about the claim, Roger Blind and Bill Alsip both e-mailed Cummins for a response. Cummins made some interesting comparisons between the ISB trucks and the 12 valve trucks. This is what Cummins had to say: Subject: 35259 :: Injection Pump Life
The 24 valve ISB engine in the 98 ½ Dodge has a Bosch VP44 electronic controlled fuel pump. The engine has an electronic control module connected to the pump as well as various sensors on the engine, the driveline and electronic throttle pedal. Service on the Dodge Ram has been enhanced since the engine electronics can be accessed with either Chrysler DRBIII or Cummins INSITE electronic tools.
The electronic ECM is designed for the Dodge application and other controls are not compatible and there are no interchangeable chips. Operating parameters are established by the Chrysler DRBIII or Cummins INSITE tools.
The Bosch VP44 electronic fuel pump has higher injection pressures, electronic controlled timing and fueling which allows precise, instantaneous control and provides greater responsiveness over the entire power range (extended from 2700 to 3200 rpm). This is a completely new engine design platform that combines electronic engine controls with high-pressure injection as well as high strength engine componentry.
The 24 valve design with cylinder centered fuel injection improves combustion efficiency which results in better emissions, fuel economy and performance. The VP44 is a radial-piston pump with 3 pistons. The pistons are attached to the distributor rotor and the fuel pump shaft.
The pistons ride inside a cam ring (think of a donut with a "bumpy" hole) so as the pump shaft rotates the piston carrier, the pistons are compressed towards the center, pressurizing the fuel. The pressurized fuel is then directed to the proper cylinder by the distributor rotor.
The cam ring can be rotated in a "retarded" or "advanced" direction; this is done using a solenoid valve, which modulates pressure to a fuel-pressurized piston beneath the cam ring. Also, the start and end of injection are controlled by a solenoid valve.
Although the VP44 has initially not been as reliable as we would have liked, we (and BOSCH) are confident that its reliability will improve. The VP44 is much less complicated internally than the P7100, and it has many fewer finely machined parts.
We don't know for sure that BOSCH considered low-sulfur fuel when designing the pump, since the pump is fuel lubricated and today's fuels are low-sulfur.
The VP44 is completely fuel lubricated, as the VE pump is. It does not use oil lubrication like the P7100 does. The VP44 is expected to last at least a long as the P7100 in normal automotive applications. However, we obviously have much more "long-term" experience with the P7100 than we do with the VP44, so our knowledge base is still evolving.
Soon after launch, the VP44 had its share of problems, just as the P7100 did when it was introduced, but we have worked closely with BOSCH to correct the issues with the pump, and we're confident that the VP44 will be a reliable fuel pump.
There are some significant differences between older trucks/engines and the newer trucks with the 24-valve engine. A Dodge pickup today can be 75 HP more powerful and almost 2000 lbs heavier than a 1991 W250; the weight of the trucks has increased yearly as Dodge has added safety and convenience features.
Also, the electronic controls on the 24-valve engine allow Cummins to control the power and torque very precisely across the entire RPM range. The mechanically controlled engines have their power and torque precisely controlled at torque peak and rated power RPMs, but between those two engine speeds, power and torque can often exceed the published figures.
Dodge set specific power and torque limits at particular RPMs for our engine, and with the electronic controls, we were able to meet them very accurately. This means that a mechanically controlled engine may produce more power and torque than a 24-valve engine at particular engine RPMs.
This is most noticeable when one compares the trucks back-to-back, as someone who trades in an older Cummins powered Dodge would do.
While the 24-valve engine itself is more efficient than the older mechanical engines, actual observed fuel economy may differ between older and 24-valve trucks, due to the fact that
the 24-valve trucks are generally heavier, the 24-valve trucks produce more useable power at higher RPM than the mechanical engines, allowing the driver to rev higher (the engine is not as efficient at higher RPM as it is at lower RPM), and the previously discussed torque curve differences may promote a less efficient driving style.
Thank you for choosing Cummins power or products. Please let us know if you need assistance in locating the nearest Cummins-authorized distributor or dealer. Please feel free to use our International Dealer Locator: (http://www.cummins.com/partserv/intro.html) found on the Customer Assistance page of the Cummins website (www.cummins.com).
Let us know if have other questions, or if away from your computer, feel free to call us (toll-free, from North America) at 1-800-DIESELS (343-7357), or 1-812-377-5000 (toll call, worldwide, ask for 800-DIESELS).
Regards,
--
Powermaster Customer Assistance Center
Cummins Engine Company, Inc.
Columbus, Indiana, USA
Email: -- email address removed --
I give credit to the Dodge ram.org site for the folowing page:
--------------------------------------------------------------------------------
An article appearing in the March 2000 issue of Petersons 4Wheel & Off Road quoted Dr. Diesel saying that the VP44 injector pump used on 24 Valve ISB Dodge diesel trucks was UNRELIABLE compared to the 12 valve engine's P7100 injector pump.
Curious about the claim, Roger Blind and Bill Alsip both e-mailed Cummins for a response. Cummins made some interesting comparisons between the ISB trucks and the 12 valve trucks. This is what Cummins had to say: Subject: 35259 :: Injection Pump Life
The 24 valve ISB engine in the 98 ½ Dodge has a Bosch VP44 electronic controlled fuel pump. The engine has an electronic control module connected to the pump as well as various sensors on the engine, the driveline and electronic throttle pedal. Service on the Dodge Ram has been enhanced since the engine electronics can be accessed with either Chrysler DRBIII or Cummins INSITE electronic tools.
The electronic ECM is designed for the Dodge application and other controls are not compatible and there are no interchangeable chips. Operating parameters are established by the Chrysler DRBIII or Cummins INSITE tools.
The Bosch VP44 electronic fuel pump has higher injection pressures, electronic controlled timing and fueling which allows precise, instantaneous control and provides greater responsiveness over the entire power range (extended from 2700 to 3200 rpm). This is a completely new engine design platform that combines electronic engine controls with high-pressure injection as well as high strength engine componentry.
The 24 valve design with cylinder centered fuel injection improves combustion efficiency which results in better emissions, fuel economy and performance. The VP44 is a radial-piston pump with 3 pistons. The pistons are attached to the distributor rotor and the fuel pump shaft.
The pistons ride inside a cam ring (think of a donut with a "bumpy" hole) so as the pump shaft rotates the piston carrier, the pistons are compressed towards the center, pressurizing the fuel. The pressurized fuel is then directed to the proper cylinder by the distributor rotor.
The cam ring can be rotated in a "retarded" or "advanced" direction; this is done using a solenoid valve, which modulates pressure to a fuel-pressurized piston beneath the cam ring. Also, the start and end of injection are controlled by a solenoid valve.
Although the VP44 has initially not been as reliable as we would have liked, we (and BOSCH) are confident that its reliability will improve. The VP44 is much less complicated internally than the P7100, and it has many fewer finely machined parts.
We don't know for sure that BOSCH considered low-sulfur fuel when designing the pump, since the pump is fuel lubricated and today's fuels are low-sulfur.
The VP44 is completely fuel lubricated, as the VE pump is. It does not use oil lubrication like the P7100 does. The VP44 is expected to last at least a long as the P7100 in normal automotive applications. However, we obviously have much more "long-term" experience with the P7100 than we do with the VP44, so our knowledge base is still evolving.
Soon after launch, the VP44 had its share of problems, just as the P7100 did when it was introduced, but we have worked closely with BOSCH to correct the issues with the pump, and we're confident that the VP44 will be a reliable fuel pump.
There are some significant differences between older trucks/engines and the newer trucks with the 24-valve engine. A Dodge pickup today can be 75 HP more powerful and almost 2000 lbs heavier than a 1991 W250; the weight of the trucks has increased yearly as Dodge has added safety and convenience features.
Also, the electronic controls on the 24-valve engine allow Cummins to control the power and torque very precisely across the entire RPM range. The mechanically controlled engines have their power and torque precisely controlled at torque peak and rated power RPMs, but between those two engine speeds, power and torque can often exceed the published figures.
Dodge set specific power and torque limits at particular RPMs for our engine, and with the electronic controls, we were able to meet them very accurately. This means that a mechanically controlled engine may produce more power and torque than a 24-valve engine at particular engine RPMs.
This is most noticeable when one compares the trucks back-to-back, as someone who trades in an older Cummins powered Dodge would do.
While the 24-valve engine itself is more efficient than the older mechanical engines, actual observed fuel economy may differ between older and 24-valve trucks, due to the fact that
the 24-valve trucks are generally heavier, the 24-valve trucks produce more useable power at higher RPM than the mechanical engines, allowing the driver to rev higher (the engine is not as efficient at higher RPM as it is at lower RPM), and the previously discussed torque curve differences may promote a less efficient driving style.
Thank you for choosing Cummins power or products. Please let us know if you need assistance in locating the nearest Cummins-authorized distributor or dealer. Please feel free to use our International Dealer Locator: (http://www.cummins.com/partserv/intro.html) found on the Customer Assistance page of the Cummins website (www.cummins.com).
Let us know if have other questions, or if away from your computer, feel free to call us (toll-free, from North America) at 1-800-DIESELS (343-7357), or 1-812-377-5000 (toll call, worldwide, ask for 800-DIESELS).
Regards,
--
Powermaster Customer Assistance Center
Cummins Engine Company, Inc.
Columbus, Indiana, USA
Email: -- email address removed --
Last edited by a moderator:
I have not even mentioned the several Warranty repairs that I've had done to my truck. All of which, if it was an airplane, would have been fatal!!
