If you're fed up with worrying about your fuel system, these types of lml cp3 conversion instructions may help you change out that ticking time bomb of the CP4 for something a lot more reliable. Anyone who is the owner of a 2011 in order to 2016 Duramax knows the "grenade" stories. The CP4 pump motor was designed with regard to efficiency and high pressure, but it doesn't handle air or poor fuel high quality well at almost all. When it fails, it doesn't just stop working; this sheds metal shavings throughout your entire gas system, ruining the injectors, the bed rails, as well as the lines. It's a five-thousand-dollar nightmare that nobody desires.
Switching in order to a CP3 water pump is basically the gold standard intended for bulletproofing an LML. The CP3 was used in the particular older Duramax engines and is legendary with regard to its longevity. It's a bit of a job in order to get it inside, but once it's done, you may finally stop checking out your fuel filter systems for "glitter" each time one does an oil change.
Getting your workspace and tools ready
Before a person dive into the engine bay, let's talk about exactly what you're getting straight into. This isn't a thirty-minute oil change. You're going to be leaning over the grille for a couple hours, so a top-side creeper is a lifesaver if you have one. When not, a durable step stool along with a moving blanket on the radiator support will have to do.
You'll need a standard set of metric electrical sockets and wrenches, but specifically, make certain you have the good set associated with flarenut wrenches for the energy lines. Using a regular open-end wrench tool is a superb way to round off a fitting and turn a Saturday project into a Monday early morning tow to the shop. You'll furthermore need some long extensions, a rotating or two, and a good torque wrench.
One thing individuals often overlook is usually cleanliness. Since you're opening the high-pressure fuel system, even a tiny speck of dirt may ruin an injector. Grab a couple of cans of brake solution and blow off the entire top of the engine before you start taking issues apart.
Tearing down the top end
The CP3 sits strong in the "valley" from the engine, beneath the turbo mouthpiece and the consumption plumbing. To get there, you've obtained to clear a path. Start by disconnecting your batteries—safety very first, obviously—and then start removing your invisalign aligner consumption ducting.
You'll have to pull the turbo mouthpiece and the EGR plumbing if a person still have this. It's a great deal of bolts, and some of them are in places that will require small fingers or a large amount of patience. Keep a magnetic tray nearby due to the fact dropping a bolt into the area is a ceremony of passage you definitely want to prevent.
Once the intake stuff is definitely out of the particular way, you'll see the fuel track and the CP4 pump tucked method back there. You'll need to disconnect the high-pressure ranges. This is where those flarenut wrenches come in handy. Take your time here. The particular lines can be stubborn, and the last thing you want to do will be kink one.
Removing the particular CP4 pump
Now we're getting to the heart associated with the matter. The particular CP4 is held in by three mounting bolts. They will aren't particularly hard to see, but they can be the pain to reach. You might need to move some wires harnesses out of the way to get a clear shot at them.
Once the bolts are away, the pump should be loose, yet it's still mounted on the drive equipment. Most lml cp3 conversion instructions will tell you that you don't necessarily have to pull the whole front timing cover, which is a huge relief. A person can usually access the pump equipment through the essential oil fill neck or a dedicated access hole, depending on your specific setup. You'll need to unbolt the gear from the pump shaft—just be careful not really to let the gear drop to the engine case. Usually, this stays wear the idler gear, but it's worth being cautious.
With the gear unbolted, you can slip the CP4 out. It's heavier as opposed to the way it looks, therefore about the grip upon it. Once it's out, take a second to look at the area. It's most likely pretty grimy lower there, so provide it a quick wipe before you try to seat the new pump.
Installing the CP3 and the adapter plate
The CP3 wasn't originally made to bolt directly to the LML block, which explains why your conversion kit comes with a good adapter plate. This particular is an important piece of the problem. You'll want in order to bolt the adapter plate to the CP3 first, ensuring the particular O-rings are sitting down perfectly and lubed with a little little bit of clean diesel powered or assembly lube.
Slide the CP3 into location. It's a limited fit, and you might have to wiggle it around the particular wiring harnesses. Once it's seated against the engine stop, start your installation bolts by hand. Never ever make use of an impact to start these; you perform not wish to cross-thread anything in the area.
After the push is secured, you'll need to reattach the gear. Most CP3 pumps use a slightly different nut or washing machine setup than the CP4, so inspect kit's specific hardware. Rpm it right down to the specs provided within your kit—usually, this really is around 50-60 ft-lbs, but don't quote me on that will, check your paperwork!
Plumbing and the big wires trick
Today comes the part where most people obtain tripped up: the particular fuel lines and the wiring. The particular CP3 has its fuel inlets plus outlets in different spots than the CP4. Your kit should include brand-new high-pressure lines and maybe some soft tubes for the return side. Route these types of carefully. You want to make certain they aren't massaging against any sharp edges or vibrating contrary to the block, since that can lead in order to leaks later on.
The biggest "gotcha" with the LML CP3 swap is the Fuel Control Actuator (FCA) . Upon a CP4, the regulator is "normally closed, " yet on a CP3, it's "normally open" (or vice versa, according to the year). Essentially, they work in opposite directions.
In case you simply plug the oem harness straight into the CP3, the truck might start, but it can immediately go directly into limp mode or even run at full rail pressure, which sounds like the bag of hammers hitting your motor. You have two options here: a few kits come with a plug-and-play wires adapter that reverses the polarity, while some require you to swap the hooks in the connection. It's a basic fix, but in the event that you forget it, you're likely to have got a stressful first start.
Tuning and the first start
You can not run a CP3 with an LML without a custom tune. Since the pump responds in a different way towards the ECU's instructions, the computer needs to be told precisely what's going on. You'll need to flash a "CP3 conversion tune" onto the truck prior to you even try to crank it over. Most reputable enthusiasts can get this particular to you pretty very easily.
Once the tune is loaded, it's time for you to perfect the system. Because you had the whole valley open, there's a lot of air in the lines. Make use of the primer bulb on top associated with the fuel filtration system housing until it's rock hard. Give it a few cranks, but don't overwork the starter. It might take a few tries to get the air away of the high-pressure side.
When it finally fire up, it may run a bit rough for a minute while the last from the air flow bubbles work their way through the injectors. Keep an vision on the area with a torch to make certain there aren't any leaks. If every thing looks dry and the rail stress is steady on your monitor, you're good to go.
Final thoughts within the swap
The very first time you get the truck with regard to a spin right after following these lml cp3 conversion instructions , you'll probably observe well, not much. And that's the particular point. The pickup truck should drive simply as well as it did before, but with one major difference: you don't have to worry about your fuel system exploding every time you hit the gas.
It's a huge job, and it's certainly not really the cheapest mod you can do, but for the peace of thoughts alone, it's value every penny. You've basically taken the one major "weak link" of the LML Duramax and replaced it with a component that's known to proceed for 300, 500 miles without getting drenched in sweat. Now you may get back in order to using your truck intended for what was meant for—hauling, towing, and traveling without staring with the dash waiting around for a "Reduced Engine Power" light.