I set the idle as low as 600 RPM, went very rich on the mixture (black plugs) and dropped one spark plug heat range. Still would diesel badly, and at 600 rpm idle it sounded like garbage. And yes i know how to properly sync the SU's. I was told by an old volvo mechanic that worked on the B18's back in the day that they would sometimes diesel back in the day even. So with todays USA fuel i suppose i should not be surprised. I have excellent performance everywhere else so i am fine with using the fast idle cam to set my idle and then drop it before shutdown. I am not willing to sacrifice that performance just to attain normal idle situation, that and i have tried all the tricks, timing, mixture, spark plugs, idle speed, etc. Some of them would diesel less or not all the time but then overall performance was lacking. None of the fixes always prevented the diesel, and i am not talking a little pop, my engine will restart and run (sometimes backwards) for 10-30 seconds sometimes very roughly, and popping the clutch in gear is not a good fix. Driveline shock is just asking for problems. I even installed an "Anti-run on" Valve from Moss motors, it leaked badly from brand new so it leaned out my mixture and almost caused serious damage.