Bosch VP44 Injection Pump Requirements
I'm going to do a quick article on requirements for long life from a Bosch VP44 injection pump. Here is the list of thing that are required to keeping a Bosch VP44 injection pump happy in your Cummins powered Truck.
- Fuel Pressure
- Fuel Filtration
- Fuel Lubricity
- Clean DC Power
I know there is a lot of controversy about fuel pressure but I'm going to be to the point I suggest 14-20 PSI for optimal return flow for proper cooling and lubrication of the VP44.
With the all the different fuel pump and fuel systems out there. I've been quite pleased with my Airdog fuel system. I've got a pre-filter and water separator before the pump then the 3-micron filter after the Air Dog pump. Then I kept the stock filter as well and dropped a 10-micron Fleetguard filter in place. This has worked flawlessly on polishing fuel for the Bosch VP44 Injection Pump. Also being the AirDog flows a majority back to the fuel tank it tends to continually polish the fuel in the tank. I always will suggest in purchasing fuel from a high volume station like truck stops.
Bosch back in the day when designing the Bosch VP44 injection pump they based the design off of Europian fuel standards of 460 HFRR or less. Just about the time the Bosch VP44 was being introduced to the Cummins engine the US fuel was not adhering to any standards. So even before ULSD (ultra low sulfur diesel) came to be the US fuel had numbers as high as 500-600 HFRR. After a whole diesel industry getting damaged by the fuel the US standard was made at 520 HFRR. But that not going to meet the Bosch standards of <450 HFRR. So hence, the 2 cycle oil concept was born to band-aid this issue.
Clean DC Power
There have been so many years where people made claims of the electronics in the Bosch VP44 failed because of heat cycles. Well, that might have been true. Never the less there is another killer that I've uncovered is how clean is your power? Batteries are clean DC power just as they are but when you hook an alternator to the batteries there is always going to be some sort of ripple from AC waveform being converted to DC power. As alternators age the diodes start to fail and more and more AC power starts to leak out. I've set the limit at no higher than 0.1 AC volts measured at the batteries. The whole AC power problem could create these codes.