I've noticed in the 8s that lots of the data blocks are not named , if you go into the advanced measurements section does that give you a clue as to what the blocks are ?
Generally the synchronised block is in the first few blocks that come up , scroll through can you see anything that says synchronisation seen or just a plain yes or no , I use ODIS at work and that is a little obscure on the 8s .
So it does sound like in tank pump is priming from what you say and no I'm pretty sure there is no data block for priming pump pressure .....you have to use an inline guage , but at least we can hear it priming which is good .
Where you say stretched timing chains can stop the synchronisity your correct but you do normally get codes for this like .....crank / cam incoherence or crank / cam synchronisity not seen and so on .Also a poor amplitude signal from crank shaft sensor can do this if it's an a/c generation type ,or very poor cranking speed can do it also .
So at this point I would be scoping cam and crank signals but obviously you need a scope for this , but if you can see a block that shows synchronisity to be good we can sort of move on and say that's good and we are most likely not getting up to start up pressure.
Just as a tester ..... go into the rail pressure block and do a few starts ups and see what pressure it shows before it starts , thing here is that the obd data is not in real time and the start up interference at the ecm can send the vcds a bit scatty for a moment ....but let's just see what we get for the hell of it .
Where I was on about easy start ....it's more to show up a symptom, if you give it a wiff of easy start and it bangs up and runs smooth instantly it sort of shows that it is not getting rid of gobs of air , if it starts imeddatley it's more likely cranking speed or low signal coming from crank sensor the wiff of sniff just jumps it past that point .....this is not definite diagnostics but is a guide when you do not have all the diagnostic tools to hand .
Few more things to have a go at .
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