CP4 weak point and why the CP3 is the only solution.

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@californiajeeping

@californiajeeping

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Does the engine need to come out to replace this pump? If not, how much stuff needs to get removed in order to get to it?

Dealerships do terrible work and barely put stuff back where it was, so curious how much stuff I'd have to double check if they put a CP3 in mine.
It is near the top of the engine and I believe there is a silencing cover over it.

They dont have to do a whole lot to replace it but when they die it clogs the injectors. Not sure why they change the lines when you could run a pipe cleaner or brush through. They likely do this as an extra step. If someone was smart they would rebuild the gen 3 eco injectors after they shithouse. That would reduce the parts shortage and down time.

 

Zybane

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It is near the top of the engine and I believe there is a silencing cover over it.

They dont have to do a whole lot to replace it but when they die it clogs the injectors. Not sure why they change the lines when you could run a pipe cleaner or brush through. They likely do this as an extra step. If someone was smart they would rebuild the gen 3 eco injectors after they shithouse. That would reduce the parts shortage and down time.
I've read that they've had failures when they first tried to clean the lines. Apparently there were still metal shavings after the cleaning so they went to the "replace everything" approach.
 

rharr

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I've read that they've had failures when they first tried to clean the lines. Apparently there were still metal shavings after the cleaning so they went to the "replace everything" approach.
Yes this was discussed in the video to, cost's less in the long run to replace with fresh then to risk doing the work over and paying for things twice.

If it's easy to get to, do a S&S redirect head swap on the current one and carry a spare CP4.2 with a S&S head if it fails in the wild.
 

Rusty PW

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Yes this was discussed in the video to, cost's less in the long run to replace with fresh then to risk doing the work over and paying for things twice.

If it's easy to get to, do a S&S redirect head swap on the current one and carry a spare CP4.2 with a S&S head if it fails in the wild.
You have a link for this? i can't find anything on it.
 


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When do these typically fail or is not a mileage related failure? Keeping an eye on these threads as my diesel is creeping towards 20k.
 

rharr

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they are like a stick of old dynamite, might be good for 50 years or go boom in 8 hrs. Seems if you get a particularly bad batch of diesel it makes them go faster. All you can do is hang on, cross your fingers and use a additive.
 

Escape.idiocracy

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When do these typically fail or is not a mileage related failure? Keeping an eye on these threads as my diesel is creeping towards 20k.
2.0 Cjaa tdi’s have a cp4 pump as well. Though they have a cp3 conversion out….. 🤷🏽‍♂️ We have had 3, sold one a year ago…. Collectively over 400k miles and knock on wood- haven’t had a failure. EDT or diesel kleen in every tank. Model years are 2012,13,&14… so going on 10 years old.

with the tdi I am less concerned/worried- I can pull a full donor motor and trans for under $2k…. 🤷🏽‍♂️ The jeeps 3.0 does not have the availability so once a 3 kit comes out we will likely swap over as a preventative.
 

Lost1wing

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Fuel quality is key to keeping the CP4 alive. There are plenty of high mileage CP4's out there proving is a good pump. The CP3 can handle a few dry runs, bad fuel or even a little gas diluted diesel.​
The Duramax world has a redesigned fuel pressure regulator that is supposed to catch debris during a failure of a CP4 pump. Saves the injectors basically so they say. Stories on the Duramax site still talk about total destruction even with the redesigned FPR.​
The CP3 conversion on the Duramax is dealing with a missing a fuel pressure sensor so you leave a sensor hooked up and program the ecu to ignore the missing value. This is info from a forum and not an installer. I can see there being some differences in the 3.0l CP4 fuel pumps from the CP3 as well.​
Fuel quality is key! Don't run it dry, change the fuel filter as scheduled and use good fuel from reliable sources.​
I thought about the 3.0, but I am glad to have the 3.6 gas, even with the cam issue.​

 

 
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