What should fuel pressure be under load?
Under load the fuel pressure should hit the set point of the regulator & stay within a few psi no matter what the load or engine rpm. At speed the fuel pressure also should react to manifold pressure.
When does fuel pressure build up in a Mercedes?
You will notice that the fuel pressure didn’t change much when RPMs were kept constant at 4000, 2000 and idle, which is a good sign. *Note that under normal operation the fuel pressure should build up as soon as you turn on the ignition before you even try to crank the engine.
What’s the boost pressure on a Mercedes Benz Turbo?
The reason for this is very simple the turbo is spinning at 2750 rps (per second) at normal boost pressures and flow rates (not maximum) rpms translate to approx 165,000 per minute. The micro sensor for boost pressure is capable of up to 500 samplings per second due to the extremely rapid response of the VNT type turbos.
Where is the fuel regulator on a Mercedes CDI?
The Mercedes CDI series of diesel engines have an electronically controlled fuel pressure regulator mounted on the end of the fuel distribution rail. This controls, as the name suggests, the fuel rail pressure.
What causes a Mercedes Benz fuel pump to fail?
Typically problems related to the fuel pump and fuel pressure include: Under normal operation conditions, the fuel pump provides a constant flow of fuel. A failing fuel pump typically delivers too little fuel from the gas tank or in certain cases too much. Mercedes-Benz cars use an electrical fuel pump to pump the fuel to the fuel injectors.
What happens when a Mercedes fuel pressure regulator fails?
A failing fuel pressure regulator in your Mercedes will begin to throw off the engine’s air fuel ratio, which can lead to more frequent engine misfires. A misfiring engine can lead to faster wear and tear on engine components and lead to expensive repairs next time you take your car in for service.
The reason for this is very simple the turbo is spinning at 2750 rps (per second) at normal boost pressures and flow rates (not maximum) rpms translate to approx 165,000 per minute. The micro sensor for boost pressure is capable of up to 500 samplings per second due to the extremely rapid response of the VNT type turbos.
How does a Mercedes Benz Fuel pressure test work?
A fuel pressure check on your Mercedes-Benz will tell you if the fuel pressure is withing range or not. For this test, you will need a fuel pressure gauge. The Actron CP7818 fuel tester works on most Mercedes-Benz and has the required Schrader valve required for MB cars.
Why does my Mercedes Sprinter have low pressure?
Although not completely faulty, the sensor must have been signalling incorrect pressure readings back to the ECU that was cutting the engine, when the LP pressure measurement reached its switching threshold, the engine picked up again and the whole vicious circle ensued.