I had the same problem more or less this past year; flooding on a hot start. Couldn't trouble shoot it myself, so took it to a Volvo dealer. mechanic checked all the mechanicals; fuel pressure, injectors, vacuum, etc. All OK. Next step was to go pin by pin on the control board and look for a fault from one of the sensors. Not wanting to spend more time and money with this, I asked the chances of it being the temp sensor. He thought greater than 50/50. I went to parts, asked for a temp sensor. Went to check with the mechanic if this was the right part. He didn't think so, thought it was the temp sender instead. He pulled the plug on the sensor to verify. Voila! There it was. One of the clips of the plug had been mashed back and was not making contact with one of the sensor's pins; therefore it would always start cold, i.e dump fuel, regardless of the actual engine temp. He soldered in a new clip and I've not dealt with that problem since. Two hours searching, ten minutes fix.