What causes low fuel rail pressure on Duramax?
What is happening to cause this? The direct answer in most cases: Injectors. Simply put, the backflow or return rate is excessive so the pump does not keep up and rail pressure drops. Our testing of suspect injectors has shown backflow rates of 2x the factory spec or more.
What is low fuel rail pressure?
The fuel rail comes with a sensor that monitors its fuel pressure and change the pump speed accordingly. A problem usually caused by the fuel pump, fuel supply pipe blockage, fuel pressure regulator or mechanical fault. Low fuel pressure is actually what causes the PCM to activate the Check Engine light.
How do you check the fuel pressure on a 6.6 Duramax?
High Pressure Testing (LB7 Example) Start by first stroking the hand pump. If the hand pump is soft and then becomes hard, recheck cranking fuel rail pressure. If pressure is now okay, you have a fuel supply issue. Testing the high side with a supply side fault will definitely lead to an incorrect diagnosis.
What does the p0087 code on the fuel rail mean?
A sensor on the fuel rail measures fuel pressure. It will warn the PCM if the pressure falls below the level expected of the fuel pump driver module or fuel pump assembly’s current activity. In response, the PCM may log the P0087 code.
What’s the low fuel pressure code on a Duramax?
Duramax LBZ and LMM P0087 Low Fuel Pressure code Summer comes, temps rise, and the working trucks with relatively high miles start to set a P0087 code and go into limp mode while towing. I am on the receiving end of continuous calls over the past few years inquiring what to do.
How to diagnose a GMC fuel rail malfunction?
First diagnose P0087 GMC code Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins. P0087 GMC Tech Notes There is a factory service bulletin for the P0087 Code.
What is the code for the fuel rail?
Note: Code P0087 is a generic code specified by the Society of Automotive Engineers (SAE). Depending on the car manufacturer, the code’s definition may change. The PCM keeps track of the pressure levels within the fuel rail.