before throwing plugs at it, make sure it's not running too rich. One common problem with D-Jet cars is when it acts out, it runs rich. It could be the computer, map sensor, throttle position switch or fuel pressure regulator.

There is a great write up on how to diagnose this on the BW W116 forum that was posted by Nuts4Benz. Check it out.

Also make sure that your timing is set correctly. It needs to be something like 18 degrees advance at 1500rpm.

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With best regards

Al