Cp4 health

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Mar 18, 2025 | 11:34 AM

speakerfritz

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Cp4 health

Just posting today’s cp4 health status

last line

requested vs actual is almost spot on.

Mar 18, 2025 | 12:06 PM

kayakingpoodle

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From: Up in Texas

I think you should monitor the duty cycle of the metering valve too, if you can, the commanded vs actual will be super close as long as the metering valve can make it happen, as the pump output goes down the duty cycle of the metering valve will increase to compensate until it can't and then you will see disparity in commanded vs actual pressure.

Kind of like the old tbi systems with IAC motors and idle issues due to passage coking from the egr. Just check the IAC counts while scanning for codes and you'd know if it was time to decoke the throttle body.

Mar 18, 2025 | 02:29 PM

jollyrogr

Cargo Master

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Also it is easier to maintain pressure at no load. See how it maintains pressure under load.

Mar 19, 2025 | 11:24 AM

Gladstone

Mountain Pass

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Good idea looking at command vs actual. I think checking maximum rail pressure at full load is also a good diagnostic. If the peak pressure degrades even though at lower pressures command is close to actual its a sign the pump may be in trouble. My 2024 peaks at 36.9K psi.

Mar 19, 2025 | 11:26 AM

acdii

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Needs a cleaning, fuzzy.

Mar 19, 2025 | 03:52 PM

augam

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Quote:

Originally Posted by Gladstone

Good idea looking at command vs actual. I think checking maximum rail pressure at full load is also a good diagnostic. If the peak pressure degrades even though at lower pressures command is close to actual its a sign the pump may be in trouble. My 2024 peaks at 36.9K psi.

Interesting

Mar 20, 2025 | 02:51 PM

Stinson1

Mountain Pass

Joined: Mar 2017

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I monitor A vs D while on long trips from home and while towing. I have an S&S filter kit, so I want to know that my pump is failing before it locks up and spins my crank gear turning into an entire engine replacement. I think this is the major flaw with the disaster prevention kit not too many people talk about. While it is nice that my truck will still start and run with a failing pump to get out of traffic or off the roadway, it is at a risk that it spins the crank gear.