Howdy, I have the 6 cyl. version of the beloved VW IDI motor in my Volvo 740 TD. I just had the pump rebuilt (excessive drive shaft play) and injectors recalibrated. Everything's back together and I'm trying to decide what to use for pump timing. The factory manual stated 0.75mm for all cars equipped with EGR. My car has EGR, but the system is not all there. Before the rebuild I was timed at 0.80-0.85 (I can't remember). From what I have read, increasing pump timing will give me better economy and more power, but increase full throttle smoke (not much of a concern since I'm running biodiesel). Pump timing opinions anyone?? I timed it to 0.75mm and it seems a little slow, unresponsive, whatever.
the 4 cylinders can be times up to 1.00mm without problems. if youre engine and pump are basically the same plus 2 cylinders, maybe you could try 1.00mm as well?
What am I sacrificing by increasing my timing? Afterall, as the saying goes, "there's no such thing as a free lunch".