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- Bosch PE Inline Pump

- Inline Pumps General

Inline Diesel pumps are the Holy Grail for Vegetable oils use!

These pumps have proved very reliable, and are made in a variety of sizes, and by different makers.

All share the general appearance of the Bosch PE above. They are available as single element units, and multi cylinder units up to 8 cylinder, and in some cases more.

Needing little in the way of modification, these pumps work extremely well on Vegetable oils, even unheated, in a single tank scenario

- BOSCH EPVE for Turbo Applications

- Identification

This is the Popular Bosch EPVE, Axial Plunger Distributor Injection Pump.

EPVE stands for Einspritz-Pumpen Verteller, or Diesel pumps distributor.

These pumps are perhaps the best Rotary type on Veggie based fuels due to the way the main pumping element operates.

The Bosch is easy to identify due to its large square hydraulic head, ( the portion on the right in the above image, where the high pressure injector lines attach) The bracket to the right of the pump is normally bolted to the pump but has been removed to clarify the picture.

There are quite a few variations of this pump, some may have different attachements and additional systems, but all share the heavy cast hydraulic head. The Turbo version is charicterised by the diaphragm unit at the top of the pump.

- BOSCH VP44 Radial Plunger Fly By Wire Electronic Pump

- VP44 Cutaway



Easy to identify, there is no mechanical connection to the pump from the accelerator pedal, and very small cast flange to which the high pressure delivery lines attach. It is a compact and very capable pump when working correctly, often being used in very large applications such as buses and lorries, as well as Ford Focus to name but one!.

The VP44 is a fully electronic controlled pump. Early units had two ECU 's one internal to the pump and an external engine or vehicle mounted unit. Later pumps combine both ECU's in the pump case.

Being still relatively new, and untill recently, no service information or spare parts has been available, little is known as to its capability for use on Vegetable oils. Issues of pump problems associated with Biodiesel have been reported, where the methanol content attacks internal position sensors.

What is known, of failures on Diesel fuel, suggest a lubrication issue of the distributor rotor similar to the Lucas/CAV series. In common with the Lucas pumps, Fuel and hence lubrication is cut off to the rotorhead during conditions of overrun (engine braking)

Research also suggests any restriction in fuel supply to the pump, for instance a partial filter blockage could also cause damage to the pump, through lubrication starvation.

Early models were quite prone to failing on Diesel, and the distributor rotor assy, has been through three different updates since the pump was first made. Later pumps are therefore more reliable in this respect, but care must be excersised if attempting the use of Vegetable oils with these pumps.  

-Ive just received a VP44, that Ive recently won on Ebay for the huge sum of 99p! It is intended for a Volvo FL250 Tractor Unit, and was manufactured late February 03, but I have other plans for it, such as a full strip-down and assessment for Vegetable oil use!

A preliminary inspection has been carried out, and found that the distributor rotor is of a similar size to the Lucas/CAV series, and as such, will probably cause trouble with cold oils

There appears to be a similarity in construction to both the Lucas/CAV,  DPC and the Stanadyne DB 2 series

The Position Sensor appears to be a Hall-Effect device, similar to that used in Video Recorders, where they are used as reel-table rotation sensors. It is connected to the main FPCU ( fuel pump control unit, mounted at the top of the pump) by a rather delicate ribbon cable, of the type commonly used in Domestic Electronic equipment At present it is not understood what effect Methanol has on this sensor. If anyone has a VP44 position sensor thats failed on BioDiesel, --Please contact me so as  I can compare it with a known good sensor to find its failure mode.

Sensor update, The Position sensor appears to be a set up of three coils, and not a Hall effect device as previously thought. The Average DC resistance of these is around 77-85 ohms.

A suspect dead VP44 pump can be tested before removal from the engine by first disconnecting the main plug, and locating pins 6 and 7. These are at the right hand side of the socket on the pump when looking at the socket with the pump top uppermost. The pins are numbered in the socket.

Connect a lead from a good earth or Batt - to pin 6

Connect a lead from Batt + to pin 7, Make sure the lead has a good contact, and capable of passing up to 30A, also, make sure it wont come loose when the engine starts, Dont allow it to come into contact with any other pin, or earth while connected to the battery!

tie back the plug that normally goes to the pump, to prevent shorts.

Operate engine starter, If engine starts and idles correctly, then there is a good chance the pump is fine.

Most problems are associated with bad connections, as some pass high currents which are prone to trouble. The contacts in the pump plug can work loose, but can be tightened carefully with a very small screw-driver.

----More soon!



- Lucas DPC Euro Radial Plunger Pump

- Lucas/Delphi/CAV, DPC Radial plunger pump. for Turbo Applications.

Identifyable by its small footprint, and cylindrical body, the DPC is one of the more popular types of injection pump in the United Kingdom and Europe. Not all models in this range have all the features of the pump pictured, such as the throttle damper, (cylindrical black item at an angle in the picture), but all have a round section to which the high pressure fuel delivery lines attach.

This Injection pump is not so well suited to the greater viscosity of Vegetable oils. The main issue is lubrication of the large diameter distributor rotor section within the hydraulic head. This runs with very tight clearances and relies on the fuel pumped for cooling and lubrication, leaking around the shaft. Any deficiencies in lubrication can cause local overheating, which due to its smaller mass, affects the rotor more than the hydraulic head, thus the rotor expands to a greater extent than the hydraulic head. This lessens the already very small clearances, which places even more shear on the lubrication film, and a situation soon arises where the oil film breaks down completely. This can and does cause the rotor to seize in the hydraulic head.

Another issue with these pumps is that under conditions of over-run, (engine braking), The fuel supply and hence lubrication is cut off from the rotor head completely!

If the running clearances of the rotor is increased, this will cause more leakage and the pressure developed during the delivery phase may not be sufficient for correct operation, especially when the pump is at full operating temperature and the vegetable oil is thin, or when standard diesel fuel is used.

In an Unmodified condition, these pumps should only be used in a twin-tank scenario, and vegetable oil heating applied. The fuel should only be changed over when the pump is at full operating temperature, and switched back to diesel to completely purge the pump of vegetable oil before shut down, so that diesel is present for the next cold start.

I have developed a specific modification to address the lubrication issue of this series of fuel pump whereby alterations to the distributor rotor to increase available lubrication, without increasing the overall running clearance. This modification however, is not a DIY type alteration, as specialist skills equipment and parts are needed, after which the completed fuel pump will need full re-calibration on a 'Test-Bench' such as a Hartridge 2000 or similar.  The pump can then operate succesessfully on vegetable oil from cold, in a single tank scenario. As this is a very labour intensive operation it is in most cases not economically a viable option

If you are a business, interested in licencing out this modification, I would be pleased to discuss your requirements.

- Bosch VP37 EDC Pump

- Bosch VP37

This is the electronic version of the popular EP-VE, and shares the same pumping mechanism.

There is no direct connection from the throttle to the pump. Control is done via an ECU mounted somewhere in the vehicle, Places such as under driver's seat and within footwells have been used to hide away the ECU!

As these are basically mechaniclly the same as the EP-VE, they are fairly suitable for veggy use, but as there are some electrical components like actuators and position potentiometers, it must be kept in mind that any fuel used must be free of moisture...

- Bosch VP30 EDC Pump.

- The Bosch VP30 series.
This fuel pump can be thought of as an  updated VP37. It still retains the original EP-VE style high pressure pumping plan as the '37, and is suitable for veggy use. This pump differs from the '37 in that it contains its own ECU, The FPCM, or Fuel Pump Control Module. This communicates with the main engine ECU via a Bosch derived Protocol known as CAN-Bus, in a similar way to the VP44 series above. This as with all fuel injection equipment, must be supplied with clean and dry oil/fuels.

© A.C. Bowlie-Evans

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