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Garage => Mechanicals => Topic started by: Rob Smith on 21 May 2022, 04:43 PM

Title: egine rough at idle.
Post by: Rob Smith on 21 May 2022, 04:43 PM
I'm having an issue with my 1973 450se. When started cold, idle is really rough sounds like a few plugs not firing and #4 and #8 plugs sooty. The temp gauge is erratic and doesn't seem to move any.   I haven't let it warm up because it's too rough. Any help would be appreciated.

Thanks
Title: Re: egine rough at idle.
Post by: s class on 07 August 2022, 02:31 PM
Djet is notorious for running rich when cold, which leads to the fouled plugs.  You can try leaning it out a bit at the ecu and/or mps.  You could also try going one heat range up on the spark plugs.  A contributor often is a tired AAV that isn't giving enough additional idle air when cold.