I think i'd sum it up by saying a tuning box on the 2.7 restores it to how it probably was when designed it before the wick got turned down for production!!!
Timbo let me pick your brain a second.
I have Tunit II and run it usually at max setting, which according to the Tunit guys is to screw to the right unbtil engine note rises, then back it off about 1.5-2 turns. It certainly seems to have a lot of extra shove at that setting.
However, during summer when I was running an SVO mix, I had to back it off 10-15 turns to stop the engine from 'fluffing' - non-technical term but essentially, if I was in a slow queue of traffic and constantly blipping the throttle to move forward a few feet, it took a while longer for the revs to return to tickover and it 'wa-wa-wa-wa-wa'd its way as the revs died away.
Pure diesel was fine and I could revert to the standard setting. I've noted, however, the same thing happening with pure diesel when its cold, although nowhere near as badly.
My question is, is this just some kind of overfuelling thing that I can ignore because fuelling rate will be fine under normal load, or is it something else?
It strikes me the setup of these gizmos is a bit hit and miss in the absence of the (expensive) rolling road setup that Tunit otherwise recommends, I mean I can't see how making an adjustment at tickover is going to take account of, say, mods like big bore exhaust etc.. that can take advantage of better fuelling...I was always led to believe that these things were a bit more scientific than the infamous five quid resistor....
