How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Marty Your Own Question
Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53944
Experience:  Bosch Certified Master Tech. Over 35 years experience.
Type Your Mercedes Question Here...
Marty is online now
A new question is answered every 9 seconds

I have a 1988 Mercedes 56SL that I allowed to sit two years.

Customer Question

I have a 1988 Mercedes 56SL that I allowed to sit for approximately two years. I installed a new battery but only occasionally started the car. Now I want to move the car. I had the battery charged, put gas in the car, primed it with quickstart. It would run until quickstart was used up. I want to take it to the shop would like to know a little about the fuel pump. I believe it has two fuel pumps. My question is what tests should be run to determine if the fuel pumps are bad or something else?
Submitted: 1 year ago.
Category: Mercedes
Expert:  Marty replied 1 year ago.

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.

Let me know if you have any questions. Please note that you must click on a positive rating for my service in order to credit me for my help.


Related Mercedes Questions