Here are a couple more graphs, Im not sure whether they come up with names or not on here so the smoother looking one is the A4 3.0TDi hot start for a comparison and the wobbly one is the A8 doing a hot start with Easy start. It cranked over for ages then just as it was about to stop if banged then ran away fine.
Whether it would have started on its own without the easystart is open to question as very occasionally it does. engine temp was down to 70ish on the gauge - I wasnt logging it on vcds though. It did pop and wheeze a couple of times as it burned the ether so I'm inclined to think it was that.
what I notice with the graph though, its cranks over steadily at 147 rpm, pressure is steady at 75.9 bar, rising to our old friend 82.8 bar at 12.08 seconds. at 12.96 seconds though, the revs jump to 210, pressure to 103.5 then bang it starts, i assume this is the easy start. At 13.27 seconds its doing 882 rpm and 243 bar and then runs pretty much exactly on the specified line.
Is the duty cycle of the IMV as measured by VCDS the actual opening of the valve or just what it is being told to do and not neccesarily what is actually happening? It seems odd to my brain that it can work perfectly when its stinking hot but as soon as its switched off and tried again it appears not to work. It seems logical to me that there is something else holding off the start process but I lack enough knowledge of the thing and I certainly defer to your frankly amazing expertise and understanding mechanicolee - especially when you dont have the thing in front of you.
I didnt do the hammer test or the plug out test as once it had surprised me by starting on theeasy start i didnt want to shut it down again. once the OH is back home i can move the car from the farmyard back into the drive. I will try both methods then and will also log a jump start as that is likely how it will start anyway.
Last edited by erubus; 16th August 2017 at 07:25 PM.
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