BenzWorld Junior Member
Date registered: Mar 2010
Vehicle: 1993 300E sedan
Location: Melbourne Australia/ Cebu city Philippines
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
1994 E320 rough running
I need some help with a 1994 E320. It has the straight six 300E engine.
The car starts easily and runs reasonably well when cold but runs roughly when warm.
The idle is irregular , too fast in park or neutral, dropping sharply when in drive and worse when the airconditioning is turned on or power steering in use, in other words whenever a load is put on the engine.
When the car is warm I have to turn off the airconditioning at traffic lights and put the car in neutral so I can rraise the revs to stop it dying.
I have replaced the idle air speed control valve relay and cleaned the idle valve.
I have replaced the high tension leads, distributor cap , and rotor.
Still no change.
Also the car blows black smoke when floored..it is powerful and smooth when pushed but the smoke looks like a Mitsubishi Pajero diesel( with apologies to Mitsubishi owners).
I intend to re check the operation of the idle valve, and maybe replace the oxygen sensor.
Am I barking up the wrong tree?
Any help will be appreciated thanks.