Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi, step one is to check to see if the pumps are running when you crank the motor. Step two would be to perform a fuel pressure test to see if the pumps are providing adequate pressure. If you don't have a fuel pressure gauge you could remove the fuel return line at the fuel distributor and perform a fuel volume test. To perform the test you would need to connect a hose to the fuel return outlet at the fuel distributor and route it into a container then bypass the fuel pump relay so the pumps run continuously and measure the amount of fuel after 30 seconds. If the pumps are good you should collect at least 1 liter of fuel in 30 seconds. It would not be unusual for the pumps to fail after sitting for so long.
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