[Tripp]

I have a 1986 560SL and it recently began stalling. I can drive for about 2 minutes stalls out and after a minute or so, cranks back up and same thing. Battery completely died so and didn't seem to stall when hooked up to another car via jumper cables.

I replaced the battery and first drive of 20 minutes did fine.

Tried to drive an hour or so later and now back to stalling again.

Any ideas? altenator? How to check?

 

[nobby]

I have a 1986 560SL and it recently began stalling. I can drive for about 2 minutes stalls out and after a minute or so, cranks back up and same thing. Battery completely died so and didn't seem to stall when hooked up to another car via jumper cables.

I replaced the battery and first drive of 20 minutes did fine.

Tried to drive an hour or so later and now back to stalling again.

Any ideas? altenator? How to check?

Simple test with a multimeter on the battery posts when off...should be 12.6V and running should be 13.8 ish.

You could have a bad Fuel Pump Relay that heats up and fails until cooled off.

Will it stay running at idle?

 

[RickC3]

I have a 1986 560SL and it recently began stalling. I can drive for about 2 minutes stalls out and after a minute or so, cranks back up and same thing. Battery completely died so and didn't seem to stall when hooked up to another car via jumper cables.

I replaced the battery and first drive of 20 minutes did fine.

Tried to drive an hour or so later and now back to stalling again.

Any ideas? altenator? How to check?

This may/may not be related, but thought I’d offer. I experienced same on ’86 560sel with only 34k miles, which had been sitting in storage for six years. After replacing entire fuel delivery system, battery, testing fuel pump relay, replacing brass filter at end of hard line at fuel injection, stalling continued. Car would start, idle and run great, stall after a mile, then start again. Removed fuel tank & cleaned, flushed fuel tank vent line at bottom of tank & it was clogged with a greenish algae looking substance. I then replaced fuel tank vent valve and purge valve. Car now runs great.Fuel Tank Vent valve 1234700393. Purge Valve 1074700893.

 

[twosnap]

1000 different causes but I had a very similar issue not long ago that was kicking my ass on my '88 560SL. Would run fine for a bit, then super rough and stall. Turned the car off, started back up just fine and off I went....only to repeat 10 minutes later.

Turns out the ground wires on the opt of the intake (see pic) were not clean / secure. Got them dressed up and tight and no more problems. May not be your cause, but only a 1 minute exercise anyway.

Good luck!!