Low rail pressure could be caused by a restricted fuel filter, air in the fuel, a bad pressure relief valve, excessive return fuel from the injectors or a worn CP3 pump. The least likely cause would be a fuel rail pressure sensor.
Why is GM buying back L5P Duramax?
The reason? An apparent hydro-lock, no-start issue associated with the newest version of the L5P Duramax has been cited. On April 21, GM began buying back the affected ’22 model Chevrolet and GMC HD trucks, and a stop-sale order has halted all ’22 sales going forward.
Is 200 000 miles alot for a Duramax?
Even when used extensively for towing and hauling, Powerstroke, Cummins and Duramax diesel trucks typically last well beyond 100,000 miles. Because of that, it’s not uncommon to see diesel pickups with 200,000 and even 300,000 miles commanding good resale values on the used truck market.
What problems do LML Duramax have?
Duramax LML Reliability
The biggest concern on any LML is the CP4 internally combusting. The associated cost of this is about $10k and it’s not covered under warranty because it is caused by poor fuel.
What causes low fuel rail pressure on a Duramax? – Related Questions
How many miles will a Duramax LML last?
GM 6.6-Liter Duramax LML: Main Bearings
GM says a properly maintained LML should see more than 200,000 miles of service in “rough-duty cycle” before needing a major overhaul.
How many miles will an LML last?
Aside from the CP4. 2 injection pump, LML Duramax was a reliable motor that could last 300,000 to 400,000 miles when properly maintained.
What year Duramax is most reliable?
Some engines are more popular than others. For example, the pre-emissions Duramax engines made between 2001 and 2007 are highly sought-after for superior reliability.
How often should my LML Regen?
On an LML the active regen process initiates once 42 grams of soot have collected in the DPF or after 700 miles without active regen (whichever comes first).
Why do CP4 pumps fail?
Air in the pump means that metal rubs against metal, causing accelerated wear. This will eventually cause the CP4 to fail, often around 100,000 miles. Before it fails, metal shavings are produced by the CP4, which travel into the fuel injectors and the fuel lines with catastrophic results.
Should I delete LML?
Outside of expensive repairs these emissions systems also create a lot of backpressure in the exhaust system which is bad for the turbocharger. For both preventative maintenance and performance reasons, deleting the Duramax LML DPF system is popular.
How long should I let my LML warm up?
Allow Time to Warm Up the Engine
As a general rule of thumb, if it is below zero degrees Fahrenheit, you should allow your engine up to seven minutes to warm up. If the temperature is between zero and fifty degrees, the warm-up period should be three to five minutes.
How much HP can a LML handle?
On the plus side, the piezoelectric injectors in the LML can support more horsepower, pound-for-pound, than the ’01-’10 solenoid valve injectors can, so once you find more high-pressure fuel volume (and air in the form of a bigger turbo) the factory injectors can easily support more than 600rwhp.
How much does it cost to CP3 swap LML?
The cost of doing just the LML CP4. 2-to-CP3 conversion is about $3,500 for parts and labor.
How do I know if my CP3 is failing?
Check rail pressure when the engine is off. It should be zero PSI, plus or minus 500 PSI. Look for low or no supply pressure, supply pump or fuel filter etc. Excess particulates can be a factor during excessive idle time due to injector tips having a build up of carbon due to the cold.
How many miles does a CP3 pump last?
The Bosch CP3, used on the ’01-to-’10 Duramax and ’03-to-current Cummins engines, is known to last 250,000 miles or more before needing to be replaced. Of course, performance enthusiasts also know these pumps are only capable of supporting approximately 500 hp.
Does a stock LML need a lift pump?
Either way, a lift pump is required to make anything over *500 RWHP with your LML. The reality is that the pump simply can’t keep up without a lift pump if you want more power than that. From our testing, we have found the peak horsepower with a stock turbo is 520 RWHP if you want to keep your LML reliable.
How do I know if my LML has a blown head gasket?
A simple test is to put the engine under a good load at operating temperature, then shut it down and let the engine cool off for 8 hours or more. If the upper rad hose is still firm and opening the coolant reservoir cap releases air and pressure, the head gaskets have almost certainly failed.
How much boost can a stock LML turbo handle?
The LML turbo also employs a 270-degree thrust bearing (vs. a 360-degree version), which means lower durability in high drive pressure situations. Still, as long as peak boost is limited to 35 psi, the LML turbo is just as stout as its predecessors.
Can you put a CP3 on an LML Duramax?
S&S Diesel Motorsport offers the first CARB-compliant (EO #D-756) 50 State CP3 conversion available for the LML. This includes all hardware necessary to replace the troublesome CP4 with a bulletproof CP3, requires no tuning changes, and still maintains factory emissions control equipment for $2,600 MAP.
What year did Duramax stop using CP4 pump?
The CP4 was standard equipment on the 2011-present Ford 6.7L Powerstroke. From 2011-2016 GM also used the CP4 in the LML & LGH Duramax engines, switching to the Denso HP4 in 2017 when the L5P was released.