Engine mis-fire

My 1989 300te chugs when I start the motor and any time after that when I accelerate from a stop. Once it reaches 900 rpm it runs just fine. It does have new a new cap,rotor, plugs and filters.
The problem does not occur if I let the car sit for a few days,but it always comes back. Any Help?

[pentoman]

I would probably change the leads after the plugs with these symptoms. Try it, it's the next step and worth doing if you are diagnosing ignition problems like this

Good luck, let us know what works

Russ