MSefi.com read only forum (Jan.15,2018)

I have a 2.0 16v VW and I can't seem to get it to start easily when the engine is hot. A starting point would help. Should it start better with more or less fuel. Less being 2 ms more being more than that?

This has always been an challenging issue, both with carbs and FI.
GM had even went so far as to put a "hot-soak" bypass valve on their carbs back in the 70s-80s.
It was a thermal bimetal spring valve on the lower rear body that would open due to the heat soaked air up by the air cleaner (behind the secondaries on 4BBls) It could flow almost 1/4 of the volume of a primary, so quite a bit of extra air (read lean) for those first several seconds/minute after the trip to the grocery store, ATM or as Lance suggested the gas station.

Mazda uses a small bypass air solnoid to lower fuel pressure on hot start up for 20 seconds to get the hot boiling fuel back to the tank and push fresh gas back in, thats how most oem do it I believe, the ecm compensates for the lowered fuel pressure by increasing the pw slightly.