Unlike it’s competition, Cummins uses a inline engine, meaning all 6-cylinders are in one line. Otherwise, OEM is fine and will be a bit cheaper than upgraded injectors. If you’re trying to make more power, get an upgraded set. Your two options are: replacing the injectors with an OEM set, or running upgraded performance injectors. At this point, its only a matter of time before the others fail. Dropping a new injector in with a set of old worn ones can also create some performance issues if the old injectors are also worn. If you have 125,000 miles on your current set of injectors, they are likely all operating below spec from normal wear and tear. While this might make sense if you have one fail really early on a new set, we don’t usually recommend it for older engines. Because of this, it’s not uncommon for people to replace only the bad fuel injectors. When fuel injectors fail, they fail one at a time.

Unfortunately fuel injectors run $300+ per injector….which equates to nearly $2k per set without install. Poor idling and performance, surging, etc.Cummins 5.9 Faulty Fuel Injector Symptoms This can cause the injectors to either leak and drip fuel into the engine, or clog and not provide enough fuel to each cylinder.įuel injectors on the 5.9 24v are known to fail around the 150,000 mile mark. If you don’t frequently change your fuel filters the dirt in the fuel can easily get clogged in the injectors. With the 5.9’s fuel pumps flowing north of 25,000psi, the injectors face a significant amount of stress.ĭiesel fuel isn’t always the cleanest or most refined fuel which means it’s not uncommon for it to contain some dirt particles and other unwanted sediments. As discussed above, the fuel injectors are responsible for spraying highly pressurized fuel into the engines cylinders. Leaking Fuel Injectors – Cummins 24vĭespite the reliability of the Cummins 5.9, its fuel system is its Achilles heel. With that being said, given the cost of replacing the OEM pump, you’re better off with the added reliability (and performance) created by aftermarket systems.Īftermarket Lift Pumps: 2. By doing so, the issues with the engine heat and pull distance are mitigated. While aftermarket systems can get rather expensive, most will relocate the pump closer to the gas tank. Hard starting or engine stalling while runningĪftermarket lift pumps are very common among Cummins owners.2005+ model years relocated their lift pumps to inside the gas tank which greatly improved reliability. This created a lot of undue stress on the pump, ultimately resulting in premature failure. Because of this, they were: (1) subject to a lot of excess heat, and (2) had to pull fuel a very long distance. These early year 24v’s had their lift pumps attached to the engine block. However, 1998 to 2004 model year 24v’s experience common lift pump failure. In order to have a reliable fuel injection system, the Cummins 5.9 comes from the factory with an OEM lift pump. This creates an immense amount of stress on the system and ultimately crushes injection pump reliability. Without a lift pump, the injection pump has to pull the fuel all the way from the gas tank to the fuel injectors. Lift pumps are responsible for pumping fuel from the gas tank to the injection pump. Injection pumps will pressurize fuel anywhere from 15,000 to 30,000 psi, which is extremely high. The injection pump, also known as a high-pressure fuel pump, is responsible for pressurizing the fuel which gets sent to the injectors and into the cylinders. The Cummins 24v fuel injection system has three primary components: a lift pump, an injection pump, and injectors. Accelerator Pedal Position Sensor Failure.4 Most Common Cummins 24v 5.9L Engine Problems Despite the smaller powerplant, these engines are still capable of producing significant power, and tend to be more reliable than its competitors. Ford’s Powerstroke, and Chevy’s Duramax engine both use tradition V-shaped engines and have 8-cylinders instead of 6. The Cummins diesel engine is unique in the diesel truck world, as it is uses an inline design and only features 6 cylinders. Therefore, the Cummins ISB 5.9 is also commonly known as the 24v, or 24-valve. The engine continued in production until 2007 when it was retired for the 6.7L Cummins, primarily due to increased emissions regulations. The ISB 5.9 featured an inline-6 cylinder engine with multi-valve pushrods, and 4 valves per cylinder. Here is our article on Cummins 5.9 12v engine problems. Midway through 1998, the 6BT was replaced with the ISB, which stands for “Interact System B”. Each cylinder had 2 valves, hence the name 12-valve. First generation versions were named the 6BT but also commonly referred to as the 12v, or 12-valve. 24 hour tire shop tampa.The Cummins 5.9L “B-Series” diesel engine was produced from 1984 up until 2007.

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