After driving say 7 miles and the engine is not hot or any other unusual thing but once you stop the engine and you want to restart it in a minute or so it won't without waiting say 20 minutes but it does turn over normally.

did you ever get an answer, This question is posted on many fourums, but no answers. I am having this exact problem now.

Its the carb im 17 and have worked on my volvo for 3 years now and stated to stop and not start again. Take it to your dealer or do it at home(like i did) it getas really dirty after many yeqars and it should start back up as new i know mine does.

Busman, your injection system, not carb, is the problem. Possible trouble spots: (1)main fuel pump bad and/or overheating (2) in-tank pump (if you have a Bosch sys.) bad and or blocked screen (3) main fuel filter plugged up. START POINT-replace main filter, and see whyat gives. Good luck