560sl. poor idle, numerous what if posts. Lately had trouble with the starter, and the car bogging down on acceleration. Changed out the fuel filter and went for a ride. No better on accel, maybe even a little worse. Now the starter is even worse so I'm thinking at least check the battery first.

I opened the flip out in the trunk and the battery looked brand new-but....hey, what this plunger looking thing mounted next to the gas inlet? The handle is clearly out-so what have I got to lose.

I pushed it in, cranked it and voila-like new, no bad crank, immediate startup, took it for a spin and it drove like a new car-ok, cept' for the brakes and the mediocre idle.

Cheapest fix I ever did. What is it, and what did I do? (I assume it's some sort of fuel safety valve that I should have opened before I messed with the filter (I did open the cap..)

Thanks. I'm gonna sleep well tonight.

j. Boggs