My 1999 E300 developed a leak at the injector pump (fuel delivery valve). After the mechanic replaced and torx all the delivery valve the car started with a heavy black exhaust smoke. He run the car for 20 minutes or so but the exhaust never cleared.
I check you form and found M Booth direction for the proper installation technic of the delivery valve. The mechanic reseal the delivery valves an follow the procedure. The car finally run without the black smoke but idled really rough.
We bought new o-rings and seal and redo the process. Then the black smoke came back with the check engine light which reads multiple cylinder misfire.
someone, help please.....