W140 M120 Inconstant problem with engine
 

Hi all

I have a W140 M120 1992 - LH-jetronic, distributors etc.

And there is a inconstant problem - engine may work fine, but may suddenly start to misfire, and there is always different cylinders (and amount of it) - from both parts of engine.

Two ways to stop it - restart engine (from 1 or 2 restart instant normal working) or untwist it to 3000 rpm and more.

Found, that if I drive evenly - chance of misfire is more than if I drive with many stops (a lot of traffic ligths for example)

I had to connect computer - no errors, all data is ok. Dictributors caps, coils, wires, plugs, fuel filtres (tank and in-line) were changed - no result. Fuel pressure is 3.5 bars and is constant.

What's the problem? That can it be? Also strange, that each head has different EZL, LH, sensors etc. In advance, thanks for help. :)