300sl 24v wont staret when hot

[muso58]

car starts fine runs smooth until reaches norm temp. then a blip of the throttle causes it to cut out ,after that it wont start . changed coil .changed plugs ,ascertained steady spark at plugs ,with a timing light. been suggested may be B11/2 sensor. can anyone suggest test procedure for this i have a good multimeter.also could do with idea on location of diagnostic connector. is this obd2 as i have some diagnostic equipment. is thislikely to show up on a diagnostic check. any help greatly appreciated . fault finding steps etc
thnaksfor looking