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CP4 to CP-ISB21S3 (revised CP3) change for 2021 6.7L Diesel Trucks -- Merged Threads

RVTRKN said:
Lift is in the fuel tank. Has been scanned for codes?
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Scanned no codes… the problem seems to mostly persist when outside temperature dips to freezing or just below. All filters have been changed, but had very small particles of sand/dirt in the 1st phased filter but main filter on the engine showed no contamination.
 
Where do purchase your fuel? I just changed my filters at 3% remaining on the gauge, and even though it wasn't white, I could not see any large particles in my 1st filter. I was looking for possible evidence of the CP4.2 failure, but it was relatively clean. Cheap fuel can be very dirty, it will also have a yellowish look to it. I know of a fuel station in Parker AZ that has an average of $.20 per gallon cheaper than the others near it, and the fuel is yellowish/orange in color. My buddy bought the fuel when he was in Parker AZ without any issues, I warned him about the condition of the fuel, but he purchased it anyway. I only purchase top brand name fuel, regardless of cost, mainly because of the CP4.2.
 
RVTRKN said:
Where do purchase your fuel? I just changed my filters at 3% remaining on the gauge, and even though it wasn't white, I could not see any large particles in my 1st filter. I was looking for possible evidence of the CP4.2 failure, but it was relatively clean. Cheap fuel can be very dirty, it will also have a yellowish look to it. I know of a fuel station in Parker AZ that has an average of $.20 per gallon cheaper than the others near it, and the fuel is yellowish/orange in color. My buddy bought the fuel when he was in Parker AZ without any issues, I warned him about the condition of the fuel, but he purchased it anyway. I only purchase top brand name fuel, regardless of cost, mainly because of the CP4.2.
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how do you know the quality of the fuel before you buy? are there recommended brands/stations that speak more to the quality of fuel?

The only bit of advice I've received is fill up where you see truckers often fill up - or truck specific fuel stations
 
I don't remember if I posted this on this thread, but I'll repost it for you. I only buy Shell, Mobil or Chevron fuel or affiliated brands. Not because its the best or cleanest, but they are backed by the their warranty with added protection of a Credit card purchase. The issue with the CP4.2 is the main reason for my choice of brands. Truck stops aren't necessarily the best fuel but they do go through a lot of fuel in a day, its the guaranty of fuel I wanted. The independent station I mentioned in Parker was in 2006, but they still sell fuel and it still looks dirty. After the recall repair to the newer pump, I'll relax my strict fuel purchases, after a few months, incase the newer pump has issues as well.
 
98GTSViper said:
how do you know the quality of the fuel before you buy? are there recommended brands/stations that speak more to the quality of fuel?

The only bit of advice I've received is fill up where you see truckers often fill up - or truck specific fuel stations
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Not trying to hijack the thread. But a quick start to your search on diesel quality.
www.toptiergas.com

Diesel Brands - TOP TIER™

TOP TIER™ detergent reduces deposits, increases lubricity, and improves fuel stability for a cleaner diesel fuel.
www.toptiergas.com www.toptiergas.com
 
Here is what my experience is. I spoke to tech that did the cp4 warranty for me. He stated only use top tier diesel fuel only. That is what I used from Costco only for years with periodic fuel from other top tier stations . He was extremely impressed and surprised when he did fuel sample test for warranty repair as to how clear & clean my fuel was in the tank and fuel system. My advice is to use ony top tier fuel. They cannot deny claim due to bad fuel issues. You have to research brand name fuel companies tier ratings. Hope this helps.
 
Anyone noticing a loss of power and/or fuel mileage after the "fix" of going to the cp3.3 pump? I know the cp4 pump is supposed to have a higher pressure which should atomize fuel better to be able to create more power/fuel mileage. Stands to reason the cp3.3 would do less?
 
Sqrl$$ said:
Anyone noticing a loss of power and/or fuel mileage after the "fix" of going to the cp3.3 pump? I know the cp4 pump is supposed to have a higher pressure which should atomize fuel better to be able to create more power/fuel mileage. Stands to reason the cp3.3 would do less?
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On the contrary, I am getting better mileage (both unladen and towing) and the truck seems to run smoother -- 2019 Laramie 3500 with the Standard Output Cummins.
All the 2021-2022 models have the new CP-ISB21 pump, and there are no issues I have heard of.
 
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Mine is running great and I'm getting 20 to 22 MPG on the highway (not towing of coarse), 2020 2500 standard output.
 
Did yours fail?
Allamuchy_Joe said:
On the contrary, I am getting better mileage (both unladen and towing) and the truck seems to run smoother -- 2019 Laramie 3500 with the Standard Output Cummins.
All the 2021-2022 models have the new CP-ISB21 pump, and there are no issues I have heard of.
Click to expand...
 
Sqrl$$ said:
Anyone noticing a loss of power and/or fuel mileage after the "fix" of going to the cp3.3 pump? I know the cp4 pump is supposed to have a higher pressure which should atomize fuel better to be able to create more power/fuel mileage. Stands to reason the cp3.3 would do less?
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From what i have seen from friends the CP3.3 makes similar line pressures as the CP4 unlike the older variations of the CP3 as they have changed max psi throughout the years
 
Some regen much more often after the replacement, any chance you been watching your DPF screen to see if that’s the case?
 
H3LZSN1P3R said:
From what i have seen from friends the CP3.3 makes similar line pressures as the CP4 unlike the older variations of the CP3 as they have changed max psi throughout the years
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This! Pre '19 CP3 and the new CP3.3 are not quite the same pumps.

My MPGs are down but only because of the extra idling due to freezing temps here in Alberta.
 
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