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Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53899
Experience:  Bosch Certified Master Tech. Over 35 years experience.
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I have a 1980 mbz 450sl I changed fuel pump and fuel pump

Customer Question

I have a 1980 mbz 450sl I changed fuel pump and fuel pump relay. sometimes when I try to start the car it wont start, and I don't hear the fuel pump turn on but sometimes if I use the old relay it will start but not always.
JA: Does the engine turn over? How old is the battery?
Customer: yes the battery about 5 years old
JA: What is the model of your '80 Mercedes?
Customer: 450sl 1980
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: yes new fuel pump fuel pump relay and new fuel filter.
JA: Anything else you think the mechanic should know?
Customer: sometimes it starts normal and sometimes the fuel pump wont come.
Submitted: 1 year ago.
Category: Mercedes
Expert:  Marty replied 1 year ago.

Hi, my name is***** you are sure the fuel pump does not turn on try disconnecting the blue plug on the side of the air flow meter. If the car starts every time you will need to remove the air flow meter to adjust the safety contact. You can leave the connector disconnected but the fuel pump will run all the time when the key is on. The contact was installed to kill the fuel supply in the event of an accident and the vehicle stalled.

Let me know if it works. Please remember to rate my service in order for the website to compensate me for answering your question.


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