W126 300 SE running issue

[ironduke]

Hi

Just acquired a 300 SE (1990) to keep my SEC company.

It's a bit of a project so today I stuck a new set of plugs in and a decent battery to start it up. It started on the button and idles fine, however if you stab the throttle it coughs and runs poorly. If on the other hand you build the revs gently it's totally smooth and revs through to 6k.

Any ideas where to look first? First though is throttle body, sticky butterfly valve?

Thanks!

 

[syncropaddy]

Damp distributor cap, worn rotor arm and fuel filter would be the first places I would look. Then I would look at air flow throttle potentiometer on the throttle body