Why does CP4 need timed?

why does cp4 need timed

Why does CP4 need timed?

@redwngr With some changes they made with the LML engines, the cp4 is timed and is supposed to help harmonics and hard part breakages supposedly. With a cp3 on prior trucks they were not timed.

Why is CP4 timed?

The CP4. 2 must be timed with both the engine’s crankshaft and camshaft to coincide perfectly with the injectors opening, and in both the 6.7L Power Stroke and LML Duramax the pump is driven by the engine’s camshaft.

Why does a diesel pump need to be timed?

Advancing the system will cause diesel to inject into the cylinder sooner than usual, also causing the combustion phase to occur quicker. A timing advance shows the number of degrees before the piston reaches top dead center and ignition takes place.

How common is CP4 failure?

But how common is CP4 failure? The CP4 has been documented to fail mostly in cases of 100,000 miles in the USA. Other forums have disclosed that the failure rate is within 5-7%, specifically for LML Duramax engines. Despite this, the pump is well cherished by a lot of diesel engine enthusiasts.

Is the CP4 2 better?

Although the CP4. 2 moves less fuel volume than the CP3 (roughly 20-percent less according to the output of LML Duramax CP4. 2’s), it is substantially more efficient and produces higher peak pressure (30,000 psi vs. 26,000 psi).

Why is injection timing important?

Injection timing is an important engine parameter, which significantly affects the odorous emissions. If injection starts earlier, the initial air temperature and pressure are lower so the ignition delay would increase.

How much does it cost to replace a CP4 pump?

The “CP4” injection pump, as it’s called by many, is the heart of these diesels, and in the past few years it has garnered a reputation for catastrophic failure, resulting in repair costs north of $8,000.

Is there a recall on CP4 pump?

Stellantis (FCA US, LLC) is recalling approximately 222,410 units of its 2019 to 2020 Ram 2500/3500 pickups and Ram 3500/4500/5500 Chassis Cabs equipped with the 6.7-liter Cummins turbo diesel. The recall-affected trucks are equipped with the Bosch CP4 high-pressure fuel pump (HPFP) that could fail prematurely.

Will a lift pump prevent CP4 failure?

Prevent CP4.

An aftermarket lift pump system is the most affordable way to keep the CP4. 2 alive. FASS, AirDog and Fuelab are the big names in town here. Each of them offer a complete system that not only provides sufficient fuel supply pressure for the CP4.

Is the CP4 covered under warranty?

Yes they covered it. First thing they did was test for water in the diesel. When they found no water they covered the repair. He really had low mileage.

What fuel pump is in a 2021 Cummins?

Per information from owners taking delivery of 2021 Ram pickups with Cummins diesel engines, as well as photos I’ve seen on social media, it appears that Ram/Cummins have gone back to the old Bosch CP3 fuel injection pump.

What fuel pump does the 2020 Cummins have?

The factory fuel system on your 6.7L Dodge Cummins consists of your underbed fuel tank, fuel or lift pump, high pressure CP4. 2 injection pump featuring a twin piston pump that can handle up to 39,000psi, and electronically controlled injectors (simplistically put).

What happens when fuel is injected too late?

A small late-injection of diesel (<7.5 mg/cycle) had little impact on in-cylinder pressure and heat release rate (HRR). However, enhanced or retarded late-injection led to a decline in peak gas mean temperature (GMT) but an increase in later combustion temperature.

What causes injection delay?

The longer ignition delay can be caused by a number of factors including: lower intake air temperature, lower boost pressure due to turbocharger lag, lower combustion chamber wall temperature and more advanced dynamic injection timing.

Does a common rail fuel pump need to be timed?

Unlike mechanical systems these high pressure type pumps do not need to be timed with the engine as the injections timing is controlled by the ECM firing the injectors, and the pressure control valve is controlled by the ECU and varies rail pressure according to load demand.

How do I know if my CP3 pump is bad?

There may be a surge at idle due to low or no fuel supply pump pressure to the high-pressure pump. Knocking can be heard if the actual versus desired are too far apart which may be a bad FCA or Fuel Control Actuator.

How can you tell the difference between CP3 and CP4 pumps?

Basically whe a cp3 quits working it just quits without exploding. It’s typically a slow decline. The cp4 on the other hand doesn’t have a pinned piston and if it rotates slightly it tends to explode and send tiny bits of metal all through your fuel system.

Did Cummins go back to the CP3?

Not only did Stellantis, the new parent company of Ram since the FCA/PSA Group merger, find a way to revert back to the CP3 on the 6.7L Cummins engines supplied for its ’21-present trucks, but it announced a massive high-pressure fuel pump recall back in November for all ’19 and ’20 models.

What does a CP3 pump do?

The CP3 injection pump’s sole job is to create and regulate high-pressure fuel (it’s not timed with the engine’s crankshaft and camshaft). The fact that the CP3 came from Bosch’s heavy-duty line of injection pumps also speaks to its great reliability, as it was designed to play a vital role in million-mile engines.

How common is CP4 failure LML?

I have read that as much as 7% of CP4 fail on LML Duramax.

Should I put a lift pump on my LML?

Do you need a lift pump on your LML? You should strongly consider a lift pump for your LML (2011-2016 Duramax). Although there are many benefits a lift pump provides, your LML needs them for 2 main reasons, RELIABILITY & PERFORMANCE.

What happens when a CP4 pump fails?

The CP4 pump has a tendency to tear itself apart from the inside for lack of technical terms. As it begins to fail, the CP4 starts shedding metal shavings and metal contaminants into the fuel. The high-pressure fuel then leaves the pump and travels through your fuel system towards your injectors.

What happens if you don’t lubricate CP4 fuel?

Since the CP4 uses fuel as a lubricant, the lack of adequate lubrication can increase the amount of friction on the internal metal parts such as the drive cam and roller lifters. As a result, small metal particles or shavings begin to get distributed throughout the fuel system and can end in catastrophic failure.

Are Bosch CP4 pumps any good?

The CP4 was Bosch’s updated model to the incredibly reliable and well-regarded CP3 pump. Unfortunately, the CP4 has long been plagued by failures, warranty claims, and expensive repair bills, even leading to a class-action lawsuit.