Are there symptoms to a failing EZL
 

Is there a way to tel if my EZL is going bad ? Car is acting up randomly 1992 400e

Acting up?

Did the 400E's use EZLs? I thought they changed over to a newer (Siemens?) engine management system?

If you have an EZL, make sure the thing is still conducting heat away via heatsink compound. Others have commented on this.

Many people feel that EZLs are usually go/nogo. If they fail, everything comes to a standstill.

My 2c worth.

RayH

If the wiring harness is original, there is a good chance that flaky behaviour could be caused by that. The 119 runs in a very hot under-hood environment and by now most harnesses are pretty crispy.

Rgds,
Chris W.
'95 E300D, 395K

More likely, when it starts to fail, that it will fail with high underhood heat.

Dreaded crankshaft position sensor? Does the car run fine cold but miss and stumble when warmed up? How long has this been happening? Mark

Cps new, everything is pretty much new, caps rotors plugs wires air filter fuel filter fuel press reg fuel pump relay coils wires wire harness coolant sensors. Had a merc master tech look at it, might have found the problem took off the coil wires and found the connectors were not screwed on from the factory correctly he tighten them correctly and now you can't even feel the car idle, drove it twice so far so good??? Will see

Happy to hear you found the problem. I had the same thing happen with a Bosch set of wires on my 300TE---only the wire from the coil to the distributor. Took several years for the problem to manifest itself. Mark