misfires after warm up

[puffdaddy]

My 1986 300E, (I think I stated in another post it was a 1987-sorry) has a problem as follows:
When it is half way warmed up and you stop, it starts to miss. It will continue to miss until you push the accelerator to the floor. Then it runs smooth as silk until you slow down again to nearly a stop. I just replaced the OVP and now it is doing this. It seems to be getting worse. I am leaning towards plugs and wires but all my experience is in American autos, mostly GM.

[MrCjames]

If the problem occurred after you installed the OVP relay then the most likely cause may be an improperly adjusted fuel system. If the relay was defective and the vehicle was driven for any length of time while inoperable then the engine performance would have been undesirable. At that time someone may have adjusted the fuel system to compensate for the poor performance. If this was the case then the problem you are experiencing now may be a result of the KE control now being powered up thus controlling the fuel system.

Try having the fuel system adjusted with the Lambda meter OR use an ammeter to get it close. Connect the ammeter in series to one leg of the EHA, that's the device on the side of the fuel distributor. Adjust the fuel mixture so the mA reading is at or near 0, fluctuates slightly. The extreme control should be approximately 8 mA positive to 8 mA negative. Dead center of the two extreme readings would be an acceptable setting for good performance, good fuel mileage and lower emissions. This may be close enough for DIY work………………

[puffdaddy]

The fuel system was never adjusted. I have the same problem that Can-do had in 2003. I never saw his post as to what fixed it.

[Rob Pruijt]

My 300SE (1989) had the same problem.
Changed plugs, wires, cap an rotor. No more misfires.
The old wires an distributor were Beru, the failed after 10000mls. The new ones are OEM Bosch, the wires are much thicker. Also the cap is slightly different, the contacts are standing free instead of being encapsulated in the cap.

[MrCjames]

Follow Rob's lead, sounds like he resolved a similar issue.........