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Exactly! It’s sarcasm. I’m not a cp4 or 4.2 fan. There is a lot of young Duramax tuned coal rollers around along with the Dodge boys with their mirrors popped out and their big exhaust tips. There’s a lot more of the Isuzu’s sitting in the driveways with these boys that have had a failure and can’t afford to even fix their truck from the fuel system being damaged. Their all getting the same type of fuel is my point at the pumps/fuel stations. O issues with the CP3. It’s more than just lubrication.
sorry, gotcha now took it the wrong way. yeah bottom line it's a p-poor design
 
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bottom line it's a p-poor design
The fact that the CP4 can last several hundred thousands miles, I wouldn't call that a p-poor design. The design is fine, the problem is fuel quality.
 

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The fact that the CP4 can last several hundred thousands miles, I wouldn't call that a p-poor design. The design is fine, the problem is fuel quality.
Well let’s put it this way, it’s designed poorly for the fuel that we have which is what we got. Plain and simple. If they didn’t have high octane gasoline for these new small turbo charged cars like my Subaru then it would be a poor design for that era to. We don’t have the same refined fuel. The trucks are made here for here.
 

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The fact that the CP4 can last several hundred thousands miles, I wouldn't call that a p-poor design. The design is fine, the problem is fuel quality.
i disagree in that the design is fine to me its common sense when watching the video that it's going to be problematic just because of the cam and roller design i think the way the cp3 functioned made more sense with basically a stationary plunger, but no matter it's what we're stuck with
 
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Well let’s put it this way, it’s designed poorly for the fuel that we have which is what we got. Plain and simple. If they didn’t have high octane gasoline for these new small turbo charged cars like my Subaru then it would be a poor design for that era to. We don’t have the same refined fuel. The trucks are made here for here.
That's where I differ. Bosch has repeatedly said that their pumps work with our ASTM fuel. An estimated 95% of the CP4 pumps in this country are working fine, and some have reached hundreds of thousands of miles. I think the problem is that some fuel (for whatever reason) does not meet the minimum guidelines of ASTM fuel. We can blame the refinery, we can blame the distributor, we can blame the truck driver who accidental mixed gas with diesel, etc. But it is a fact that the overwhelming majority of CP4 pumps are without issue.
 

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i disagree in that the design is fine to me its common sense when watching the video that it's going to be problematic just because of the cam and roller design i think the way the cp3 functioned made more sense with basically a stationary plunger, but no matter it's what we're stuck with
I didn't say it was a great design, I said it wasn't a p-poor design. :grin2:

Ram and Cummins decided to use the CP4 pump. Trust me, they would NOT have used the CP4 if they believed it was an inferior design. :thumbsup:
 

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That's where I differ. Bosch has repeatedly said that their pumps work with our ASTM fuel. An estimated 95% of the CP4 pumps in this country are working fine, and some have reached hundreds of thousands of miles. I think the problem is that some fuel (for whatever reason) does not meet the minimum guidelines of ASTM fuel. We can blame the refinery, we can blame the distributor, we can blame the truck driver who accidental mixed gas with diesel, etc. But it is a fact that the overwhelming majority of CP4 pumps are without issue.
Tell that to the people that have had these failures. I live in a territory of great size. Less than 40,000 people total. What percentage of trucks is that, driven by these people. What percentage have a CP4 from a GM or Ford. Should be quite small, yet there is a known issue about this that is enough to here about it over and over amongst the people around me. When people have to drop 8+ grand to roll their $50,000+ truck again to get to work to make their truck payment, you here about it. What known choice did these people have to do to prevent this?
 

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If I understand it correctly, Cummins went with the CP4 to get the 1K ftlbs, which required more fuel/pressure than the CP3 was designed for. IDK, there may be more to it than that. I'm glad I got a left over 18 with the CP3.
 

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Tell that to the people that have had these failures. I live in a territory of great size. Less than 40,000 people total. What percentage of trucks is that, driven by these people. What percentage have a CP4 from a GM or Ford. Should be quite small, yet there is a known issue about this that is enough to here about it over and over amongst the people around me. When people have to drop 8+ grand to roll their $50,000+ truck again to get to work to make their truck payment, you here about it. What known choice did these people have to do to prevent this?
I understand the frustration. That's why I don't buy a GM or Ford. :grin2:

Like I said, I've been running biodiesel since 2006 for it's lubricating properties. If I don't run bio, then I run a fuel additive. That might help, but it's not a guarantee.

My next suggestion is to buy extended warranties and make sure everyone has good insurance.

And lastly, if they can't afford to keep a modern day diesel on the road, then maybe they should buy a gasoline engine. Who knows, maybe it would be cheaper to replace a gasoline engine at 300,000 mile intervals than to keep a modern day diesel on the road for 900,000 miles. :confused013:

I'll take the risk and choose the diesel. I've towed a 7,000 lb travel trailer through 17 states and over Wolf Creek Pass with the CP4 pump. I now have 75,000 miles on the odometer. Between FCA/Mopar warranties and insurance, I feel pretty good. So far, Love's fuel and the CP4 hasn't failed me yet.
 

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If I understand it correctly, Cummins went with the CP4 to get the 1K ftlbs, which required more fuel/pressure than the CP3 was designed for. IDK, there may be more to it than that. I'm glad I got a left over 18 with the CP3.

I watched the video where TFL interviewed one of the engineers at Cummins. According to Cummins, the main reason for the CP4.2 was to increase injection pressure and get the efficiency they needed.
 

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Discussion Starter #111
Dual CP3 10mm


Sent from my iPhone using Tapatalk
 

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I watched the video where TFL interviewed one of the engineers at Cummins. According to Cummins, the main reason for the CP4.2 was to increase injection pressure and get the efficiency they needed.
So Cummins had to increase efficiency because the increase in torque used more fuel. My guess is the higher the PSI the more efficiently it would burn the fuel thus burning less fuel. I just hope Cummins did not make a mistake with the CP4.
 

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...And lastly, if they can't afford to keep a modern day diesel on the road, then maybe they should buy a gasoline engine....
It's making less and less financial sense for anybody given the absurd prices for not only the trucks, but the repairs. $15,000 fuel system repairs? That's retarded. As much as I'd love a new one, I am just having a hard time justifying it anymore.
 
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I just hope Cummins did not make a mistake with the CP4.
Time will tell, but my guess is that Cummins and Ram felt comfortable with the decision. Unfortunately, it might take a few years before we really have a good idea of how they are holding up in higher mileage trucks.
 

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It's making less and less financial sense for anybody given the absurd prices for not only the trucks, but the repairs. $15,000 fuel system repairs? That's retarded. As much as I'd love a new one, I am just having a hard time justifying it anymore.
If I had a modern diesel truck, and I were outside of the warranty, then I would want $15K set aside in an emergency fund. That would give me the peace of mind to handle most expensive repairs.

Personally, I would rather deal with the possible expenses of diesel repairs than drive a Hemi.
 
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If I had a modern diesel truck, and I were outside of the warranty, then I would want $15K set aside in an emergency fund. That would give me the peace of mind to handle most expensive repairs.

Personally, I would rather deal with the possible expenses of diesel repairs than drive a Hemi.
What does outside of warranty have to do with this? Who says it’s going to be covered?
 

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What does outside of warranty have to do with this? Who says it’s going to be covered?
We are not talking about the CP4 pump in specific. Instead, we are talking about all expensive diesel repairs. If I were to keep a diesel truck outside of the warranty period, I would want to have an emergency fund to cover any unexpected repairs.

In my opinion, some people may want to consider buying a gasoline engine instead of a diesel if they feel that the repairs and maintenance are going to be a financial burden.
 

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Pardon me? I really don’t follow you.
Having a roller lifter that can rotate in its bore is a terrible design. Have you ever seen roller lifters for a camshaft that weren't joined as a pair to keep the rollers properly oriented to the cam lobes? As soon as the lifter in the CP4.2 rotates slightly, a knifing effect begins and the pumps destruction has begun.
 

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Having a roller lifter that can rotate in its bore is a terrible design. Have you ever seen roller lifters for a camshaft that weren't joined as a pair to keep the rollers properly oriented to the cam lobes? As soon as the lifter in the CP4.2 rotates slightly, a knifing effect begins and the pumps destruction has begun.
Again?.......
 

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If I understand it correctly, Cummins went with the CP4 to get the 1K ftlbs, which required more fuel/pressure than the CP3 was designed for. IDK, there may be more to it than that. I'm glad I got a left over 18 with the CP3.
that's a common misconception the cp4 does have higher pressure than the cp3 but it has less volume by 33% more or less it was an epa thing higher pressure pump will atomize fuel better and increase efficiency. they could have achieved this by going with a denso hp4 pump that is by far a superior pump in press and volume but then the money comes into play where it would have cost a lot more to switch the entire fuel system to denso than to stay with bosch
 
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