96 sl320 rough idle and nobetter running
 

38 miles ago I filled up and now the car runs rough it does not get any better when driving. It acts like a bad plug but replaced the plugs and checked the injectors. Also replace the fuel filter. If I unhook the mass air sensor it will not stay running . Any help????:mad: :dizzy2:

plug wires
 

Had a similar issue with my 91 500SL, replaced lots of parts, ended up being the plug wires..

Matt

Rough idling
 

I have the same problem and found the culprit. My mechanic replaced the Idle control valve and the switch and that solved the problem. Try it.

Lots of potential causes to throw parts at. You need someone to pull the OBD2 codes.

rough idle
 

I have had two instances of this with my 91 300sl. The first was after an oil change where they tried to check my air filter. The change place managed to leave a vacuum line that goes to the air cleaner disconnected. My mechanic reconnected and it was fixed. The second time was , I believe, from using regular and the car started missing. It was fixed by changing plugs and plug wires. Always try techron. It works very well on this mercedes and my 911sc. Look for the simple stuff first!!!

it may be the fuel you put in, i had issues with missfires tried every thing even new cats, turned out to be dodgey fuel from filling station. get your mechaninc to take a sample of fuel out from the botton of the injector rail and see if its ok..

Raj