Normal common-rail systems will operate at 5,000 psi at idle and can reach up to 30,000 psi at wide open throttle (WOT). This is how long it will take the common-rail pump to build fuel pressure to the “threshold.” The threshold for cranking is when the fuel rail pressure reaches around 5,000 psi. When the leak down occurs, the engine has to spin over for an excessive period of time in order to re-prime the injection system.Ī normal crank time in a common-rail injection system is usually around three to five seconds.
BIG CAM 350 CUMMINS HOW TO CLEAN FUEL PUMP CRACK
When the engine is shut down, the crack in the injector’s body will often cause fuel to drain back from the fuel lines and rails back to the tank. In addition, the customer may notice some fuel dilution in the oil by seeing that the oil level is rising on the dipstick. When the body is cracked, the engine will not necessarily produce a miss but will cause other problems, which can be even more difficult to pinpoint.Īlthough the injector body can be cracked, the engine may still run fine but just take an extended period of time to crank. One of the most common failures occurs when an injector body becomes cracked. However, injectors can fail in ways other than becoming just worn out or tired. In cases such as these, the scan tool generally will pinpoint the cylinder with the contribution problem. Like anything else, injectors can get tired and become weak over time.Įven though they are electronic, sometimes the mechanical components inside the injector may also become worn, cease to function properly and even fail. But some problems may be tougher than your customer - or you - think. The good thing about electronic diesels is that the technician can link up with a scan tool to analyze data in order to try to pinpoint problems. Owners often think that because diesel engines are now computer-controlled, the technician should be able to hook up a scan tool and immediately see what is going on.
BIG CAM 350 CUMMINS HOW TO CLEAN FUEL PUMP FREE
FREE Diesel Diagnosis and Repair Articles & Videos (click here)Ī phrase that customers often use is, “This is a diesel engine the problem should be easy to diagnose.” The most accurate part of that statement is that it is a diesel engine.Ĭertainly, there are some common repairs needed on specific engines that are easy to do, but that doesn’t mean everything else will be easy to diagnose.