Mopar1973Man

This article is on how to disassemble a Cummins 24v VP44 injector and thoroughly clean and then reassemble it.For starters, you need to refer back to injector removal and get all 6 Injectors removed from the engine. Once you got all six injectors out you can proceed to clean each injector. But something to be aware of there is small parts and these parts must be put back exactly the way it came apart. WARNING! Only disassemble and clean only 1 injector at a time. All the parts are tuned to that particular body. Don't mix and match parts! Then before you can remove the nut you need to remove your copper washer. This can be done with a putty knife and a hammer just lightly tap the putty knife and it should be able to pry it up enough to using the putty knife or a screwdriver. Now as I set my torque wrench for loosening and kept adding torque to the handle adjustment looking for the click and loosening of the nut. I found it at about 32 foot/pounds so I backed off to 30 foot/pounds and set the wrench. Loosen the nut. Now you need a clean area too. I set up a shop towel and an old ashtray. I filled the ashtray with Coleman fuel (Naphtha). So I would open up the injector carefully and place all the parts in the solvent to soak. Now in the picture above there is a shim that goes in the bottom below the spring. This shim might be stuck inside the body don't sweat it let in soak in the Coleman fuel for about 5 minutes and pick it up and it will fall out. Now that all the parts are soaking take an old scotch bright one that's been used a bit and rather soft. dip it in the solvent and light rub the nozzle clean of soot. Yes, you may rub the tip but be gentle about it. Now look at the pintle (needle) look at the tip for damage or wear... Now check it for smooth sliding action in the nozzle. If it feels rough rub the pintle gently with the scotch bright pad and it will help it out... I was doing a mini-spray test too... Dip the nozzle in the solvent keeping the fuel hole up and holding the nozzle horizontal using a blow gun just a light burst of air will show you your spray pattern somewhat but also ensures the nozzle tip is not plugged. Now just blow all the large parts clean and dry from the solvent. Make sure to blow the fuel passages clear. Once you happy with the clean up and every is clean now reassembly the injector exactly the way it came apart. Put your shim in the body take notice of which side was up. You'll also notice the shim has worn marks from the spring so be sure to put it back in the right way. The shim has to be this side up... Take notice to the side that has the wear mark for the spring... Then place your spring the body. Then there is a cone shaped piece that goes on top of the spring but make sure to place the hollow side up. This is for the pintle to ride in. The mid body goes on top of this take notice to the pins it will only go on one way... Then your nozzle and pintle go on top to look like this... Here is a good video of how I did each injector.

Reprime Bosch VP44 Injection Pump The Fuel System Cummins This is an article on how to reprime the Bosch VP44 Injection fuel system on a 24V Dodge Ram Turbo Cummins. A certain amount of air becomes trapped in the fuel system when fuel system components on the supply and/or high-pressure side are serviced or replaced. Primary air bleeding is accomplished using the electric fuel transfer (lift) pump. If the vehicle has been allowed to run completely out of fuel, the fuel injectors must also be bled as the fuel injection pump is not self-bleeding (priming). Servicing or replacing components on the fuel return side will not require air bleeding. DANGER! DO NOT BLEED AIR FROM THE FUEL SYSTEM OF A HOT ENGINE. Loosen, but do not remove, banjo bolt (test port fitting) holding low-pressure fuel supply line to the side of Bosch VP44 injection pump. Place a shop towel around banjo fitting to catch the excess fuel. The fuel transfer (lift) pump is self-priming: When the key is first turned on (without cranking engine), the pump operates for approximately 2 seconds and then shuts off. The pump will also operate for up to 25 seconds after the starter is quickly engaged, and then disengaged without allowing the engine to start. The pump shuts off immediately if the key is on and the engine stops running. Turn the key to CRANK position and quickly release the key to ON position before engine starts. This will operate fuel transfer pump for approximately 25 seconds. If fuel is not present at fuel supply line after 25 seconds, turn key OFF. Repeat previous step until fuel is exiting at fuel supply line. Tighten banjo bolt at fuel supply line to 24 N·m (18 ft. lbs.) torque. Primary air bleeding is now completed. Attempt to start the engine. If the engine will not start, proceed to following steps. If the engine does start, it may run erratically and be very noisy for a few minutes. This is a normal condition. Continue to next step if: The vehicle fuel tank has been allowed to run empty The Bosch VP44 fuel injection pump has been replaced High-pressure fuel lines have been replaced Vehicle has not been operated after an extended period WARNING! Do not engage the starter motor for more than 30 seconds at a time. Allow two minutes between cranking intervals. Perform previous air bleeding procedure steps using fuel transfer pump. Be sure fuel is present at fuel supply line before proceeding. Crank the engine for 30 seconds at a time to allow air trapped in the injection pump to vent out the drain manifold. DANGER! THE FUEL INJECTION PUMP SUPPLIES EXTREMELY HIGH FUEL PRESSURE TO EACH INDIVIDUAL INJECTOR THROUGH THE HIGH-PRESSURE LINES. FUEL UNDER THIS AMOUNT OF PRESSURE CAN PENETRATE THE SKIN AND CAUSE PERSONAL INJURY. WEAR SAFETY GOGGLES AND ADEQUATE PROTECTIVE CLOTHING AND AVOID CONTACT WITH FUEL SPRAY WHEN BLEEDING HIGH-PRESSURE FUEL LINES. WARNING: ENGINE MAY START WHILE CRANKING STARTER MOTOR. DANGER! ENGINE MAY START WHILE CRANKING STARTER MOTOR. The engine may start, may run erratically and be very noisy for a few minutes. This is a normal condition. Thoroughly clean area around injector fittings where they join injector connector tubes. Bleed air by loosening high-pressure fuel line fittings at cylinders number 3, 4 and 5. Continue bleeding injectors until engine runs smoothly. It may take a few minutes for the engine to run smooth. Tighten fuel line(s) at injector(s) to 38 N·m (28 ft. lbs.) torque.

Stock Lift Pump / Cummins Campaign Pump There are some serious design flaws in the stock fuel system. The stock lift pump or the Cummins Campaign pumps are both unable to supply enough fuel volume for a hungry Bosch VP44 injection pump. Part of the problem is the stock lift pump is only good for 35 GPH flow rate. However, even Bosch states that the Bosch VP44 injection pump needs at lets 70% of the fuel return to the fuel tank which is used for cooling and lubing the Bosch VP44 injection pump. So how much fuel does the Bosch VP44 injection pump consume at a WOT run? For a stock truck, you could see as high as 18-20 GPH. Now let's do some simple math. 35 GPH - 20 GPH = 15 GPH... Then 15 GPH / 35 GPH = 42% being return to the tank roughly. This is one point of failure with stock lift pumps. This last picture shows the plastic hub that normally starts to slip or breaks this is why I tell people it doesn't matter if the pump makes noise because the motor might be turning, but the pump rotor is no longer spinning. Now the other failure like this is the plastic will start to slip and pressure falls as friction builds up the plastic will melt and bond again, and the pressure rises once more. This what caused the pump above to fail was slippage of the rotor. As for the pressure regulator, I don't have a picture of this, but if you look inside the ports of the lift pump sometimes you can see the spring and check ball (BB) inside one of the ports. This body of the pump is nothing more than pot metal (cast aluminium) which the check ball rattles against the seat of the aluminium until the check ball is leaking pressure back around itself so the pump goes into constant recirculation. The Cummins Campaign Pump is a redesigned lift pump for Cummins’ engines. It was originally designed for the Buses. The campaign pump is identical to the Dodge OEM pump, which is supplied at manufacture, yet is much cheaper in price! Unfortunately, the Campaign pump is no longer available. The ones that are attainable are very expensive; due to demand, but the part number is 4090046 if you want to take your chances. Lift Pump FAQ's Q: What is the voltage to the lift supposed to be? A: Lift pump should have a constant 12 Volt supplied to it while the engine is running. During cranking the lift pump voltage is modulated 50% duty cycle to reduce starting pressure. Q: What's a stock lift pump pressure supposed to be? A: Normally, a good lift pump should be about 14-15 at idle and about 11-12 PSI at wide open throttle at 65 MPH. Q: What is the lowest lift pump fuel pressure allowed? A: No lower than 10 PSI as stated by Dodge and Cummins both. Below this pressure, Bosch VP44 injection pump damage will result. Q: How much volume does a stock lift pump provide? A: Approximately, 35 GPH Q: Is the fuel pump relay in the power distribution center the relay for the lift pump? A: No. This relay is the power supply relay for the Bosch VP44 injection pump. The lift pump has no relays and is directly controlled by the ECM. Q: How long will a stock lift pump last? A: I've seen a little at 10,000 miles, and some have reported as far 100,000 miles. However, at any rate, I would still have a fuel pressure gauge to monitor the lift pump health.