'87 560sl stall with no warning
 

I've never had this happen before. Driving car today both on highway and local roads. Got off highway and was doing about 40 when engine stopped immediately with no warning. Pulled to side of road and restarted car easily. Ran fine all the way home which took about 30 minutes. If you didn't know it had stalled you would think everything is fine.

Car has just shy of 100k miles.

I'm thinking something electrical but not sure what to start checking. The only thing i noticed is that radio reception cuts in and out but that's probably unrelated.

Thanks in advance for any help!

Common fault is over voltage relay intermittently functions, or fuel pump relay, not so common , alternator brushes of regulator worn, and check distributor cap, last coil if it happens hot , voltage should be minimum 12.7 to 14.1 while running