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Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53977
Experience:  Bosch Certified Master Tech. Over 35 years experience.
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My 89 560SL quits while driving. after a few minutes, it restarts.

Customer Question

my 89 560SL quits while driving. after a few minutes, it restarts. There is mo precursor for it to stall, at a stoplight, at speed on the highway and everywhere in between. I replaced the fuel filter (loosing about 1/2 tank on the ground while doing so.
JA: Whether it's at the end of the driveway or on the highway, a car stalling can be dangerous. The good news is the mechanics we work with have tons of experience dealing with all kinds of engine issues. How old is the battery? Does the car stall out mainly when going up or down hills?
Customer: There are no hills in Delaware.
JA: Got it. I'll pass this info along to the mechanic so that he can get you a quick fix. Are you hoping to fix this yourself?
Customer: Yes. Bought the car as a project car. Just because I own a Mercedes does not mean I can afford to own a Mercedes.
JA: Great! What have you tried so far? Is there anything else the Mercedes Mechanic should be aware of about your Mercedes?
Customer: The fuel pumps work. Smart enough to check them while they were out.
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Mercedes Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: Mercedes
Expert:  Marty replied 1 year ago.
Hi, my name is***** first thing you should do is check to see if the fuel pumps are operating when you crank the motor while the car is not starting. If the pumps are not operating you will need to replace the fuel pump relay.
Customer: replied 1 year ago.
Did you receive the complete story about what is going on or did you just get a small part of it? My 89 560sl stalls while driving down the road or while I am waiting for the light to change. While I changed the fuel filter, I checked the fuel pumps, and they are both working. The only safe way I can figure to see if the fuel pumps are working after stalling would be to put a "t" onto the fuel line and bring the "t"ed end into the car. Let's just assume that the fuel pumps are still operating properly.
Expert:  Marty replied 1 year ago.
Yes, I read the history. The pumps are controlled by the fuel pump relay. I never said you had a pump problem I said you may have a fuel pump relay problem. There are two common reasons for the SL to stall. Either a bad fuel pump relay or a bad ignition control module. You can rule out the relay by removing the relay and installing a fused jumper lead from terminal 30 to 87 in the relay connector. With the jumper installed the pumps will run continuously. If the car does not stall with the jumper in place I would replace the relay. If the car still stalls with the jumper in place I would suspect a bad ignition control module.Let me know if you have any questions. Please remember to rate my service in order for the website to credit me for taking your question.Marty