I will explain what happens when the FD starts leaking.
It usually happens overnight. Every 3-4 months after enjoying driving my mercedes I park it at home, then in the morning it starts up like crap. It hesitates, doesn't idle right then dies. I smell lots of raw fuel, so I lean the mixture.

After leaning the mixture the car starts fine but it will hesitate heavily at idle and it starts vibrating the car at acceleration as if the motor mounts are gone bad.

When the FD is leaking the hesitation is caused by the leaking fuel that enters through the airflow housing into the cylinders #2 and #3. If you look at where the leaking fuel goes to, you will see that #2 and #3 cylinder will suck all the fuel that is leaking. Consequenlty, the #1 and #4 cylinders will run lean because we adjusted them to be lean and the other two will run rich. This causes the vibrating hesitation.

Did you look into the airflow housing to see if your FD is leaking?
Can you try to lean the mixture even more?

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1989 230E, 8v, 166.000 km, updated to 94/95 trunk & hood
2002 Daewoo Nexia 50.000 km
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1987 VW Jetta GLE 16V, Recaro seats
1982 Volvo 240 DL (lovely car!)
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