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When you type at least 4-5 characters in a thread you are automatically subscribed to it and will then receive updates. I guess its just easier to do while you are there reading it anyway. That’s why you see “Subscribed” or “subbed” a lot.
 

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Great info CDMax16.

When you talked with Exergy, did they provide any details on the Improved Stock CP4.2? Wehrli rep said that will support up to 600 hp with greater output and the Safety screen. No further details beyond that.

Wonder what internals were changed for the Improved Stock and measured increase in output. I was hoping to get a better built CP4.2 (whatever that means) with the Safety screen to handle a moderate tune and mitigate failure.
Understand it's still a CP4 with a questionable design but I figure if I'm reaching the CP4, at that point, may as well drop in an improvement.

Really don't want to do a CP3 swap and all that goes with it.
The Exergy Improved stock is a stock Bosch unit with the improved MPROP. No other modifications. It might be good to 600 hp, but they (Exergy) said 500 maybe a little more.
 

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I may be wrong, and I have not found a diagram for the fuel circuit on the CP4.2 yet. This MPROP valve appears to me to filter the fuel returning to the tank not the fuel from the pump discharge to fuel rail.
 

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I may be wrong, and I have not found a diagram for the fuel circuit on the CP4.2 yet. This MPROP valve appears to me to filter the fuel returning to the tank not the fuel from the pump discharge to fuel rail.
The MPROP is is a metering valve. It meters the fuel going to the high pressure side.
 

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Off topic, but is there a reason for this comment, as opposed to using the thread tools to subscribe to the thread? What am I missing?
Lazy....makes everyone else who subscribed earlier in the thread, to waste time, data charges, and bandwidth....to load up a thread hoping to find out some new interesting comment that would aid in problem solving...and then you see....:| nothing.


Note; bored Staff have been known to search for posts with sub'd...and mass delete 'em. haha:
 

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They were convincing enough that I will be installing an upgraded MPROP on my stock CP4 this weekend. Along with a few more parts😁.
Let us know or post a DIY for this mod :smile2:

While the CP3 conversion is the ultimate fix, there are a lot of CP4’s that get a good clean supply of fuel and are running around without a problem. The problem is if a CP4 does break is the cost to fix everything. A lift pump and one or possibly both of these “fixes” will hopefully prevent that.
I'll have to go see if Google will advise as to what the HFRR specs were on the CP3. The CP4 is rated @ 460um HFRR (found on another thread). It seems US diesel (unsure if Cali is different?) is mandated @ 520um which is above the scar rating and Canada is @ 460um meeting Bosch's minimum rating. I am starting to think lubricity is the main component of failure, ofcourse water just makes this a compounded issue. Throw in dirty fuel and it's a mess. Again, this is all my uneducated opinion.
 

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Let us know or post a DIY for this mod :smile2:



I'll have to go see if I Google will advise as to what the HFRR specs were on the CP3. The CP4 is rated @ 460um HFRR (found on another thread). I see US diesel (unsure if Cali is different?) is mandated @ 500um which is above the scar rating and Canada is @ 460um meeting Bosch's minimum rating. I am starting to think lubricity is the main component of failure, ofcourse water just makes this a compounded issue.

I will keep you posted. It is on the ups truck out for delivery now.
Opti-lube XPD in every tank.
 

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I will keep you posted. It is on the ups truck out for delivery now.
Opti-lube XPD in every tank.
All the additives I've seen mention how much product to use to increase cetane points/numbers. None have mentioned how much additive is required to increase lubricity values. Guess that is subjective at best I suppose. 'dunno;
 

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Just found this on the internet which makes sense since LSD (CP3 era) went to ULSD (December 2010 - start of CP4.2 era)

"Processes used to desulphurize diesel fuel reduce the natural lubricating qualities of the diesel fuel. Since engines
require the diesel fuel to act as a lubricant for their injection systems, the diesel fuel shall have sufficient lubricity
to give adequate protection against excessive injection system wear. Additives are used to improve diesel fuel
lubricity. Lubricity additives can have unwanted side effects particularly when used at excessive concentrations or
in combination with other additives or contaminants."
 

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2. The Exergy MPROP can be installed on all LML CP 4.2’S.

3. All LML units are CP 4.2’s. The 2 stands for 2 pistons. There is a CP 4.1 that is a 1 piston pump installed in VW’s (possibly others).
Thanks. That actually clears a lot up. I’ve had four lbz trucks before but this is my first lml and I’m new to this cp4 stuff. Keep us updated on the install I’m going to order one too.
 

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Exergy MPROP. I didn’t get it until 5:00 pm, so maybe tomorrow.
 

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A close up of the screen.
 

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Looks solid.. will be interesting to see it compared to the stock screen
 

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Has Exergy actually measured the metal particles from a grenaded CP4 to confirm the 25 micron screen will catch all debris? Still skeptical at this point.
 

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Has Exergy actually measured the metal particles from a grenaded CP4 to confirm the 25 micron screen will catch all debris? Still skeptical at this point.
It won't stop all the debris, but I'm sure it will catch a lot more than stock before it plugs up. Enough to save the injectors? I don't know but I'm skeptical too. Looks like we'll have to wait until someone's cp4 bombs with one of these new screens in it 'dunno;
 

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It won't stop all the debris, but I'm sure it will catch a lot more than stock before it plugs up. Enough to save the injectors? I don't know but I'm skeptical too. Looks like we'll have to wait until someone's cp4 bombs with one of these new screens in it 'dunno;
And I hope it is not mine. At least until I get that return bypass on here.

I guess I am little skeptical as well. But I already feel better just knowing that MPROP is going in tomorrow.:grin2:
 

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It won't stop all the debris, but I'm sure it will catch a lot more than stock before it plugs up. Enough to save the injectors? I don't know but I'm skeptical too. Looks like we'll have to wait until someone's cp4 bombs with one of these new screens in it 'dunno;


I'll keep my future upgrades on a CP3 conversion for longevity. The pricing for the conversion is just way overpriced IMO. I just hope my tuner is still able to update my tunes when that time comes :thumb
 

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Well I got the new MPROP installed today, with a little help, along with deleting my grid heater and throttle valve by installing new intercooler piping. It was a little bit of a pain in the a$$, but not to bad. I only had to make one trip to the parts store.
 

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Well I got the new MPROP installed today, with a little help, along with deleting my grid heater and throttle valve by installing new intercooler piping. It was a little bit of a pain in the a$$, but not to bad. I only had to make one trip to the parts store.


Excellent. Any step by step advice? What tools did you need? I may order one of these for the hell of it. Why not.


Sent from my iPhone using Tapatalk
 
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