OK , I have not had a 560 in decades, the manual did talk about it leaking and bleeding excess fuel into the manifold, fix or replace!, its on the front of the engine has two wires, connector going to it and a pipe from the fuel distributor.
I have had 300s TDT, 560SEC, 560Sl, but untill you get an early ML (dont ask), or an early 500SEL your life has been simple. my best car so far has been a 01 E Wagon,got the 8 year 100k warranty, and broke even so far. dont know the next purchase. You can gt a lot of Cadillacs, I always drove Mercury Grand Marq. while in business, all those police cars cant be wrong. For $ 140 for a new S they will loose me. Dont get my profile wrong I have had other current MBs my wife likes the 140, due to size, I could have paid for an addition to MB or the dealer showroom, probably have! They treat me reasonably well.
MR Z get with it, check the cabs in euroe.