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_______________________________________________________________________________THOUGHTS ON HOW TO MAKE YOUR VP44 LAST LONGER After many years of trying to improve or fix the problematic VP44 Injection pump, I have made great progress, but I am frustrated that I can’t make them last forever. Computer failures are 90% of almost all drivability issues in my experience. This is from listening to all of you in the “Real World” and testing the accuracy of my diagnostic procedures daily. I am convinced that HEAT IS THE KILLLER OF THESE PUMPS, based on information I have learned over the years. I got this information by listening to all the great people who call me for technical help, and keeping track of initial as well as repeat failures. I have spent many hours and dollars trying to figure out how to solve this problem. I have tried remote mounting the computer to keep it cool, only to have it be affected by stray radio Interference. I have tried putting a cooling plate on top of the computer, like they do in big high powered computers, only to find out there isn’t enough temperature difference between the computer and underhood air temperatures to allow it to work. I tried to thermally insulate the computer and that just created more heat, so I learned that the computer itself generates the heat. Fuel flow actually cools the computer. The more horsepower or work you make the truck do, the hotter the computer gets. This DID make me realize that fueling boxes are better for making extra power than programmers because they take the heat from the added HP and dissipate it in the performance box itself, instead of the computer. Programmers put all the heat from holding the fuel solenoid closed longer into the computer on the injection pump. From my observations and experiments I truly feel that the working environment of the truck and horsepower determines the life expectancy of a VP44. A truck that lives and works in hotter parts of the country has more problems than one that lives and works in cooler regions. I DON’T know if it is just heat or “heat cycles” or both that kills computers, so I want to share an idea that MIGHT work. I think this is pretty common sense thinking, so give it a listen below. Blue Chip Diesel Performance proved in 1999 that 5 PSI, under load, made all the horsepower the VP44 pump could make, even with stock fuel lines, fittings and supply pump. We did this test on a dyno when we were testing our Fuel Management System. We thought the amount of return fuel flow at this pressure was adequate for internal lubrication. This proved to be all good information as it turned out, just not enough information. We didn’t know then what we do now, namely that of the heat issue, so we never measured the temperature of the return fuel under a variety of operating conditions. Determining the effect of volume versus cooling seems like an almost impossible test to do in a shop. As I prefer “Real World” tests anyway, here is a theory and a test that makes sense to me. You be the judge and see if you think I might be onto something worthwhile. If you pump fuel through a line at 5 PSI a certain volume will flow, creating a certain amount of cooling for the computer. If you pump fuel through the same size line at 15 PSI, more fuel should flow and therefore offer more cooling, right??? So, let’s try using 15 PSI or so, all the time for a test to see if repeat failures are diminished or eliminated. Only time will tell, and only you the customers in the “Real World” can give me good information to share with others. It may be a few years before this becomes fact or fiction, but I think it is worth a try. I am recommending, if the customer can afford it and especially if they have had really bad luck with computers and therefore injection pumps, to pay about $105.00 more for a Fass lift pump that makes about 33% more fuel flow, according to the manufacturer. So from now on I am offering two lift pumps, one for $170 that is a third generation Carter made OEM one, or a Fass OEM replacement unit for $275, both designed to fit in the same location as the original one. Installation of either choice makes installation a lot easier than the far more expensive options. Call me when you have an opinion, to tell me how either of these choices are doing for you. Do you think your injection pump has lasted longer because of this choice of lift pump? In time you will be able to tell me if you are experiencing better durability and lower cost per mile of operation! Thanks for reading, Chip Fisher, Owner Blue Chip Diesel Performance 888-ISB- PERF or 888-472-7373 MON-FRI 9-5 Eastern Time " New Product Announcement " |
