Whose jumped into the abyss with their HPCR?

[Crunch]

The horror stories about getting diesel sprayed under my skin were enough for me, so I've never considered cracking open the HPCR system. But I'm sure at least a dozen of you have lost sleep at night wondering what it's all about.



So who's done it, and what was it like? Would you now bleed the fuel lines on your own? What about change out your own injectors? Did you get crazy ideas about rigging up a flame thrower?

 

[bighammer]

Changing injectors is not a big deal. Engine off= zero pressure. Not sure that cracking lines with engine running is necessary.

 

[klenger]

The HPCR system is self priming, so there is no need to crack a line open if you run out of fuel.

 

[Vaughn MacKenzie]

Yes, if you need to prime it, open the water drain on the fuel filter canister and bump the starter until fuel comes out, the close it and crank.



I was involved with one injector change, it was easier than I expected, no leakage problems or anything. When we fired it up the first time after the swapout we did it with the hood closed. After a test drive we shut it down and then popped the hood to check for leaks. Only safe way to do it.



Vaughn

 

[mattymac]

Just remember the torque specs.



Injector securing bolt= 8mm 10nm

injector wire nut=8mm 1. 25 nm Extremely light dont break the copper stud on the injector!

rocker=10mm 34nm

male connector nut=24mm 50nm

fuel lines=19mm 30nm

intake arm=10mm 24nm

rocker box bolts=10mm 24nm

valve cover and vanity cover= 10mm 24nm

fuel line and rail securing bolt=10mm 24nm

 

[Crunch]

Originally posted by bighammer

Changing injectors is not a big deal. Engine off= zero pressure. Not sure that cracking lines with engine running is necessary.

Then there is obviously a lot I don't understand about the HPCR system. I thought that when you shut the engine down the HPCR stays pressurized. If this isn't the case, where does the pressure bleed off to when you shut down the engine?

 

[RankRam]

When the engine stops running the high pressure bleeds off and the excess fuel goes to the return line and back to the tank.

 

[Turbo Tim 1]

Realistically the HPCR system only has a "little" more pressure than the other Cummins systems so as far as safety goes the same precautions should be taken with each.



Personally I am going to fire the truck up with the hood open and stand back a little, I don't want to be a mile down the road and realize there is 6 gallons of #2 all over my engine. 30000 psi will vaporize by the time it get 5 foot away from where it leaked.



We did just do some safety training at work though where we talked about diesel fuel and compressed air injected into your body, it was pretty scary thinking of all the stupid things I've done over my llife.

 

[bighammer]

The rail bleeds off pressure at shutdown. That's why the 3rd gens crank longer than my 94 at startup. The 94 is injecting fuel right away where the 03 has to build pressure in the whole rail first.



TurboTim is right, any high pressure fuel is dangerous. A leak near your skin is not good.

 

[klenger]

My understanding for the longer crank time on the 3rd gens is that the computer needs to sync with the crankshaft position sensor before it can fire the injectors. The 2nd gens were mechanically timed by the injection pump. Maybe it's a combination of fuel pressure and timing.

 

[Yo Hoot]

It won't just get under your skin, it will remove it so fast you won't have a chance to pull back. DO NOT PLAY WITH THE LINES WHILE THE ENGINE IS RUNNING>>>> EVER!!!

 

[rbattelle]

Scarry thread! #ad

 

[Evan A. Beck]

Someone's going to end up dead. I took a couple of HPCR classes and head firsthand what can happen. Trust me guys, don't mess with the fuel system.

 

[Vaughn MacKenzie]

One thing that's easy to overlook is the fact the injection lines and fuel rail are under extreme pressure on a constant basis. Any defect or leak becomes a big problem and a danger in a hurry. If you ever end up with a cracked or broken injection line you're dead in the water too, the engine may not run at all. If it did you'd lose a ton of fuel in a hurry, most likely the system will sense low pressure in the rail and attempt full output to compensate.



All previous injection systems deliver fuel to the cylinders in pulses, so most of the time there is no pressure in the injection lines. Only for a few microseconds during the injection event. If you end up with a broken injection line, it's not the end of the world, you've got one dead cylinder and some fuel leaking but at least you can limp to safety.



Vaughn

 

[nickleinonen]

Originally posted by Vaughn MacKenzie

One thing that's easy to overlook is the fact the injection lines and fuel rail are under extreme pressure on a constant basis. Any defect or leak becomes a big problem and a danger in a hurry. If you ever end up with a cracked or broken injection line you're dead in the water too, the engine may not run at all. If it did you'd lose a ton of fuel in a hurry, most likely the system will sense low pressure in the rail and attempt full output to compensate.



All previous injection systems deliver fuel to the cylinders in pulses, so most of the time there is no pressure in the injection lines. Only for a few microseconds during the injection event. If you end up with a broken injection line, it's not the end of the world, you've got one dead cylinder and some fuel leaking but at least you can limp to safety.



Vaughn

so a few wrenches and pull the broken line off, smash it with a hammer to flat it out, fold it over its self and smash some more. reinstall it and close the hood, start up and drive away. it will weep from the "crimping" but it will hold a good bit of pressure. to let you limp home. if the line is leaking, it's NFG to start with, so smashing it/bending it some more ain't going to hurt.

 

[Turbo Tim 1]

Anyone know how to make a "Word" file so I can post it here? It has text boxes and pictures. It's pretty interesting talking about compressed air but the idea is the same.

 

[Turbo Tim 1]

Ok I figured it out here you go



#ad

 

[Turbo Tim 1]

And another



#ad

 

[thejeepdude]

I've done the same thing as both the guys in case #1 and #2 so many times I can't count, and I never had my hand inflate or get air bubbles in my blood. My hand ALWAYS have cuts in them. I've used my finger to plug my 120psi air nozzle when the valve stopped working, of course that only works with a small holed nozzle. There's got to be something they're not saying here... or else I just have thick skin. :-laf



But all that aside, 26000PSI diesel fuel is a different story... ouch.

 

[rashwor]

@#$% Scary stuff!



I have been guilty of washing parts in diesel to clean them and then blowing them off with a compressed air hose. NEVER AGAIN!



WHO'D THUNKIT?