is a VP44?
- A VP44 electronic rotary distribution pump that distributes
and meters high pressure fuel required for injection. It is
found on the 1998.5-2002 dodge Ram 2500 and 3500 light duty
trucks. The VP44 pump can also be found on several mid-range
and agricultural engines.
will void my warranty on my VP44 injection pump?
- The VP44 pumps will not be warrantied if a user taps or
splices the pump wire and does not use a stealth cover. This
is where having a BD Diesel stealth plate comes into play.
The Stealth Cover for the 1998.5 to 2002 Dodge 24V fits onto
the VP44 injection pump, providing secure, sealed connection
instead of notching the pump wire for power mods. If the wires
are cut in any way, the pump is no longer under warranty,
and any repairs that need to be made to the injection pump
will be the buyers responsibility.
much Fuel Pressure Should the VP44 Receive?
- There is a diaphragm inside the VP44 that is somewhat sensitive.
This particular diaphragm works best under pressures between
10 and 15 PSI. Some pumps will be able to run higher than
that but we donít recommend it. After changing your VP44,
if you notice continued hard starting or feel as though the
pump is getting bogged down, it is probably time to check
the lift pump pressure. Our recommendation for optimum fuel
pressure is 12 PSI of the VP44.
Thoroughbred Dieselís VP44s have new computers (PSG)?
- Before a VP44 is rebuilt the computer portion is removed
and tested. If the computer does not meet every single one
of the qualifications mandated by Bosch then the entire computer
is replaced regardless of the failed qualification. If the
computer meets all of the Bosch qualifications then it is
caused my VP44 to Fail? Is this a Common Problem?
- The most common cause of VP44 failure is lack of fuel. Dodge
trucks 98.5 and up are notorious for having weak lift pumps.
Unlike most injection pumps, the VP44 is fuel cooled and lubricated.
Therefore, if its fuel supply comes from a weak lift pump,
it is very easy for the VP44 to overheat and cause damage
to itself. This lack of fuel results in one of two types of
failure within the VP44. One is that the diaphragm inside
of the pump is damaged and does not allow the pump to build
up the appropriate amount of pressure. The second is that
the overheating causes the computer portion of the pump to
also overheat and thus, creates a communication failure between
the ECM and the Injection pump.
Thoroughbred Diesel Charge for Cores Up Front?
- Sometimes. On replacement parts that our customers order
frequently we have taken steps to prevent core charges up
front. However, on some items we do still require an upfront
core charge. Check out our core policy page.
Thoroughbred Dieselís VP44 Injection Pumps New or Rebuilt?
- Bosch is no longer casting housing’s for the VP44
injection pump. Therefore, at this time ALL VP44 injection
pumps require a used housing, also known as core, to be rebuilt.
Due to the need of a core, there is no such thing as a completely
new VP44, even though some are advertised as such.
the Injection Pumps Come With a Removal Tool?
- Our injection pumps do not come with a removal tool. Thoroughbred
recommends going to your local parts store and purchasing
a steering wheel removal tool. The threaded holes on the gear
are M8 x 1.25. You will also need a couple of bolts meeting
those specification to attach the steering wheel puller.
a Hot Rod VP44 Work On a Stock Truck?
- We don’t recommend it, however it is possible. Using
a Hot Rod VP44 on a stock truck will cause the truck to have
a very rough idle, due to the extra pressure the pump is producing.
The extra pressure is can also cause issue on stock injectors,
which is why Thoroughbred only recommends using a Hot Rod
VP44 if you have upgraded injectors designed for a higher
I Buy the Hot Rod VP44?
- If you are planning to upgrade your injectors, then yes,
you should upgrade to a Hot Rod VP44. However, for the majority
of our customers, you should not upgrade. Yes, it is very
tempting to upgrade your injection pump and get the extra
HP, but there are more effective ways to gain extra horsepower
on a stock truck. We would recommend going with a mild tuner
such as the Edge EZ which will give you the extra horsepower
and should help to increase fuel economy without any of the
side effects associated with the Hot Rod VP44.
Do I Check Lift Pump Pressure to the VP44?
- This method will vary depending on what year your truck
is. If you have a 98.5-99 Cummins there will be a 1/8 by 27
NPT port on top of the fuel filter housing. For this year
truck, this is the most accurate place to insert your fuel
pressure sensor to read the pressure supplied by your lift
pump. For trucks ranging in year 99.5-2002 fuel pressure should
be checked at the Schrader valve located on the side of the
Do I Tell If I Have a 17x or 15x VP44?
- Every Bosch pump has a data tag on one side of the pump,
drivers side when locate on the vehicle. On this tag there
will be a 10 digit Bosch number that is stamped into the metal.
The first 8 digits of this number should read 04705060. The
last two digits of this number are the identifiers on the
type of pump. If the pump is on a light duty Dodge Cummins
pickup , and the last two digits are a multiple of 7 then
the pump is a 17x. If the last two digits are not a multiple
of 7 then it will be a 15x pump. The only exception to this
will be if the engine is in an application other than a light
duty Dodge Cummins pickup. In which case, the pump could be
a 16x or agricultural model.
is Thoroughbred’s Warranty on a VP44?
- Thoroughbred Warranty on a VP44 is 1 year unlimited miles.
The two most common things that will void your warranty are
fuel contamination and inadequate fuel pressure. Both of these
issues can be prevented by upgrading the lift pump system
to either an AirDog of FASS fuel system.
is the Cause Of Hard Starts?
- Hard starts as they relate to VP44 injections pumps are
caused by lack of fuel or over pressurization by the lift
pump. If a lift pump is going bad and failing to supply the
proper amount of fuel to the injection pump, then the truck
will hard start due to lack of fuel. However, a newly installed
lift pump that is pushing over 15 PSI to the VP44 can also
cause hard starts. The VP44 is a very sensitive pump and needs
approx. 12 PSI to run properly. Once you start getting about
15 PSI to the injection pump, you actually start to over pressurize
the pump causing it to act as if you had a flooded engine.
Wire Do I Tap on a VP44?
- There are two wires running from the back of the pump up
to the computer portion on the top of the pump. This computer
portion is known as the PSG. The wire that is closest to the
engine and connects to the PSG is the wire that needs to be
tapped for installation of some modules. Keep in mind that
tapping this wire will void the warranty on your VP44. Thoroughbred
Diesel recommends installing a BD stealth cover instead of
notching the tap wire directly.