My new to me in the summer of 2020, 2007 XK car had displayed a problem in very hot weather (95 -100 F) that’s not unlike fuel vaporization. The car misses under even slight acceleration, and gets worse under heavier acceleration, to the point of stalling. It will however run fine under steady throttle, and giving it a cool off period resumes normal operation. It does not throw a code, and the check engine light does not come on. It’s been through diagnostics at the dealer but without a code they cannot help. They say it’s not fuel vaporization as that relates to fuel pressure which would throw a code. The car had new cat converters last year by the P.O. There is no insulation obviously missing in the engine compartment. I do note that the fuel line from the tank runs up beside the exhaust down pipe on the left side, but it’s in as manufactured condition.
Anybody have any ideas on this?