28/09/2020
Mercedes Fuel Pressure Test
The fuel pump plays a vital role in Mercedes-Benz cars. The fuel pump is located in the fuel tank. It pumps the gasoline from the fuel tank to the engine. While fuel pump failure isn’t very common in MB cars, we have seen several Mercedes cars such as ML320, C-Class, and E-Class models having a fuel pump go bad as early as 120k miles. In this tutorial, we will show you how todiagnose fuel-related problems and perform a fuel pressure test on Mercedes gasoline engines. If you need help diagnosing fuel problems on a diesel engine, check out this tutorial.
Mercedes Fuel Pressure Test Instructions
If you suspect that your fuel pump is not working, you need to perform a fuel pressure test to verify. 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.
This test applies to Mercedes-Benz vehicles equipped with 4-cylinder, V6, V8 and V12 gasoline engines such as M112, M113, M119, M104 M272 and M273.
IMPORTANT NOTE
Be extremely careful during this test procedure. If fuel falls on hot engine parts, you may cause a fire. Keep a fire extinguisher nearby in case of emergency. Never carry this test if the engine is hot.
Mercedes Fuel Test Procedure
Tools Required:
Fuel Pressure Tester
Step 1
Open the hood of your Mercedes-Benz. Remove the engine cover. The engine cover can be pulled up as it is held in place with four tabs and no screws.
Step 2
Locate the fuel test port on the fuel rail. If you have a hard time finding the fuel pressure port (Schrader valve) on your Mercedes, start from one of the fuel injectors and follow the fuel rail.
Step 3
Remove the Schrader valve cap. Connect your fuel pressure tester.
Step 4
If you turn the ignition ON the fuel pressure should build up, before you even crank the engine.
