Running worse!
 

I have a 1989 560 SEC and it has developed a problem as it gets up to operating tempeture. When starting from a stop it seems to stutter or stumble before taking off. When it is cold the throttle response is just about instant and smooth. It will also stutter when I have coasted to a crawl and then floor the gas. It seems to take a second and then builds up speed slowly then takes off again like it was cold. Any help would be great.
Thanks
:confused:

The wires and plugs are new. It dosent seem to be a skip, its almost like a delay before the rpms come up. The engine wont skip, I guess a hesitation is the best way to say it.

So, this stutter is actually a smooth running engine except it's like you don't have much power until the RPMs build up?

This makes me think of a fuel delivery problem....thinking injectors or very possibly dirty fuel filter.

Another avenue of checking is the rubber breather hoses the connect to the idle control valve, and the 2 hoses from the smog pump to the engine. I thought the breather hoses were made of a bakelite type material until I replaced them and the new ones were pliable rubber. The hoses from the smog pump to the engine were just old and would pop off on occaision, causing vacuum leaks that resulted in bad stutter at start-up and rough running at low rev. Good luck.

Yes the engine is smooth and the filter isnt that old. Yes I know it could get dirty under certain conditions. The engine dosent strain it just dosent react then all of a sudden it cranks out the rpms and takes off nicely. I do have a problem with the throttle switch leaving me with a high idle but thats all.
I will check the rubber hose's and change the fuel filter and see what happens.
Thanks for the ideas.
Bill