No start on the SL... No Fuel
 

After sitting for 10 days or so on 1/4 tank, the 500SL won't start. I know, I know, always leave your tank full, but I didn't this time. It drove perfectly before.

I has plenty of crank, with a good battery and fresh starter, but not even a hint of ignition. Last fall, I had a few instances where it seemed that fuel quit flowing and the car decelerated and died. It acted like it was right now, then all of the sudden, LIFE.

I took the air cleaner off and saw nothing blaring.

I'm going to put in 5 gallons of premium and see if that makes a difference. I keep track of mileage along with fuel, and it seems like I have enough. I'm wondering if I'm having an electrical problem with the EFI or my fuel pump is acting up.

Anyone had similar symptoms and solutions?

Classic Fuel pump relay.

Location? What does it look like?

You should be able to tell if it is the fuel pump relay, can you hear the pump run momentarily when you turn the key to run prior to cranking? If not, relay or the pump itself.

Got it running today, and its acting normal.

I went back to the fuel pump, and gave it a few taps and jiggles. The car fired on the first crank.

I'm not sure if my fuel pump is on the way out or I have a loose connection somewhere. Everything did look tight back there, though.

I can get a new Bosch fuel pump from my source for $180, so I'm about going with that since its original. I don't want it to stick again and strand me somewhere.

I'd replace it, if it is sticking it will happen again....

... and probably when you're not at home!

You may find the car runs better all around with the new fuel pump... the old one might not have been providing good pressures anymore.

-J