Jackaroo Diesel hot start problem

Thanks for replies.

Here's more details to queries in those replies. It cranks fast, bearing in mind that this happens only after its gone say 10 km or more, and oil is thin and batteries( two) recharged from earlier starts. Cold starts ok. Several short trips, a couple of ks, it re-starts, its only after several successive starts or one longish run of maybe 10k plus, that it then wont start. When oil is thin of course. So cranking is faster that the earlier cold start. Its not erratic, but absolutely a set repeatable pattern. It won't start after its warm, EVERY time. And it ALWAYS starts first touch of key after given some time, 15 to 20 mins to cool down, or for oil to drain down or whatever. No work done on it since its last service, and its near due for next. So no recent change to any filter. etc. They have checked in sump. apparently some Jacks develop loose or cracked pickup pipe that can suck air as oil level drops slightly as oil is pumped around engine. Such crack then covered as oil drains down, when it will start.

Think I will get it back from them and drive it about locally. It's running beautifuly, power terrific, smooth running and idle. As least no one will steal it while parked at shops and it will always be ready to start at first tun of key by time shopping is done. As long as I don't stall it at lights! But it does idle perfectly. It had wiring harness and injector oil seals replaced back about 4 years, just out of warranty but done for free, oil had got into harness. But that was different, stalled when idling . Has recently had all new injectors under Holden recall, late 2006 . Other than this strange thing its too good to part with!

Thought it might be oil pressure sensor falsely indicating to computer not enough pressure when hot.
but am told its not that. Dealers say they have liased with Holden technical head office, seems no help.
I usually use standard oil in summer, switch to a 5w... about autumn to have the thin oil for in for winter. But this is hot start not cold problem, so oil is already hot an thin when it happens. And pressure ok at idle, no flicker of oil pressure light, oil guage reading seems ok at hot idle.

Dealers will need to give me a detailed list of exactly what they have done
and times spent on each item, at very least so that anyone else looking at it won't repeat same component checks. But these dealers have had it since new, and previously found them ok. By the way, no check engine light at time of problem

I might try Robson Bros. 4wd in Benlty (WA), believe they are excellent!)

Thanks all for suggestions. It seems a strange one, its usually cold starts with Jacks, must be someone out og the thousands they sold who has same problem and cured it.