Bosch VP44 Injection Pump Cummins Application Disassembly and Reassembly

Disassembly and reassembly of a Bosch VP44 injection pump from a Cummins application. We show what the common parts look like and the common failures. The notes below dive deeper into the details of part failure causes and how to avoid them.
• If the PSG (pump mounted electronic control unit) to fuel control solenoid wires are damaged, we replace the PSG assembly
• A cracked diaphragm is caused by air in the fuel, or aerated fuel. Aerated fuel is caused by low or no engine supply pump, or lift pump pressure, plugged filter, running out of fuel etc.
• Housing advance bore damage and timing piston damage are also caused by aerated fuel. A sticky advance will not operate properly and is one cause for a P0216 code.
• Inside the pump, the pumping plungers deliver fuel by loading on the cam. The cam is moved by the timing piston, to advance the timing. If the fuel in the pump has air in it, every time the pumping plungers load on the cam, it compresses the air fuel mix behind the advance piston and causes the advance piston to slam toward the retarded side. While driving at 2000 rpm, then pump turns 1000 rpm, and the plungers load on the cam 6 times for every revolution. That means the timing piston slams retarded 6000 times per minute. It is amazing they last as long as they do with air in the fuel.
• Inside the pump, the supply pump pressurizes the fuel to operate the advance and feed the fuel control solenoid, which delivers fuel to the injectors. If the supply pump is worn, it can cause hard starting, particularly if the engine lift pump creates too much pressure (15 or more psi) at cranking.
• We check lift pump pressure with a gauge during WOT acceleration, instead of a volume test. The supply pump in the pump pulls fuel, and the lift pump on the engine pushes fuel. If the lift pump can't keep up, the pressure will drop. We consider 4 psi a minimum pressure and 8 psi to start watching the pressure. Aeration of the fuel is created by negative pressure, or cavitation.
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[@bannana6290]

omg thats my pump ty

[@ferreirasouza5792]

Amazing job

[@oregonfuelinjection]

Thank You

[@codures]

Hi, impressive work you're doing there folks. I have question : at 4:51 what torque do you set for the iat screw ?

[@joefeatherstone9646]

How is it those diagrams crack? The new ones are steel with a rubber or plastic coating are they not? I thought only the early pumps had plastic diaphragms. The check valve is for what purpose? Is it to hold fuel in the system for restarting? A bad check valve would allow the system to drain down and cause long cranks or need re bleeding?

[@oregonfuelinjection]

The new diaphragms are thicker than the old style and have a "plastic" material on one side. They are a pulsation damper to reduce the pulsations from the charging/discharging from the fuel solenoid valve. Aeration in the fuel causes more pulsations, which would cause the early style (thinner) diaphragms to crack. This would cause hard starting, which would usually be worse when hot. The overflow valve (check valve) is designed to hold pressure inside the pump and allow fuel to return to the tank for cooling of the pump. It is not a positive seal and not designed to keep fuel from draining back.

[@PeterFokuoMensah-so8qw]

It helpful thanks,have this question if a car doesn’t have good sound and is able to start what might be wrong in the car? I need help pls

[@oregonfuelinjection]

You will need to follow the diagnostics for the VP44 application. Without diagnostics being done or the vehicle in our shop, there are too many possibilities.

[@jeanl1443]

Hi, I find a calculator for static test. Witout car. For exemple 800tr min and 1800tr min for runing test. Regards

[@playerguy1232]

I wish I could send it to you guys mine🥺

[@voodorun]

How did you fix a Timing Piston housing damage?

[@oregonfuelinjection]

We replace both the housing and the timing piston, with the latest style.

[@reloadkTV]

how do you clean the pump?

[@oregonfuelinjection]

It depends on the component, it could be cleaned by bead blasting, wire wheeling, hot water wash tank, ultrasonic cleaning or rinsed in calibration fluid.

[@Th3XC45T]

i have an odd question. my vp44 will not seal where the computer plugs in. i take off the 5 (5 point security bits) and the 3 others. made sure the surface was clean installed the new o rings and it leaks through the mounting bolts. do you know of any methods to get this to seal. i have countless times. the reply will be appreciated. the part in question is the first thing removed in this video

[@oregonfuelinjection]

There are two seals, one of which is integrated into the IAT (speed) sensor. If the IAT sensor seal is leaking, then the IAT will need to be replaced and re-soldered into the PSG (computer on top of the pump). Or there is a problem with the housing, where it seals. It is a repair we can perform for you. Thanks, Mark

[@Th3XC45T]

@@oregonfuelinjection where is best to contact your shop? Id like to get more info. I have 2 pumps now that need repairs.

[@oregonfuelinjection]

@@Th3XC45T Give us a call or email - oregonfuelinjection.com/about-us/contact/

[@Th3XC45T]

@@oregonfuelinjection thanks for the info, i sent an email as im from Canada

[@enahouwa3811]

Code Défaut 0077 !!?

[@tommyduris3044]

Hi, Great vid thanks 👍 Just wanted to ask I have a Bosch VP44 059130106K 0470506038 and need a diaphragm and can't find one. Apparently it's unavailable... Can you please advise where I could get one from? I was also told I need new rollers & clamps, which funny enough are also unavailable. Is there any way by my model number you could please confirm if these parts are in fact available to buy and from where? Thank you again. It's for a 2.5 TDI 120kW

[@oregonfuelinjection]

The 0470506038 is not a USA application, so some of the parts are different from what we see. The diaphragm has been discontinued by Bosch, with no replacement noted, it was never setup in the USA price list. The rollers we have in stock, but they won't help you if the diaphragm is bad. I am not sure what clamps you are looking for? I don't have a good direction to point you in for the diaphragm...Sorry