1980 280SE missing/poor idle help

[silverfishk8]

hello.

i recently purchased a 1980 280SE euro. I have been working through the car trying to get all the issues solved, but a few remain.

the problem that worries me most is the poor idle, once the car has warmed up. after long periods of driving, it will idle very poorly (perhaps on 5 cylinders). The oil pressure gauge reads a little above 1 bar, which to me seems too low. however it runs fine while driving.

i have replaced adjusted the valves and changed plugs and wires with no change in performance. so the question is: is the engine worn (low oil pressure), or is it an ignition / fuel issue?

the odo reads 145k, but my guess is that it was switched when the car came to the US.

thanks for any help that you can provide.