My 1999 v-70 normally runs well. Very occasionally, when I switch it on, the car will not start. All the normal warning lights are illuminated but the engine does not fire up. After, maybe, 2 minutes of trying, it starts and everything appears normal. I have taken it to a dealer but they say there is nothing to check as everything is normal. I am concerned that it will not start after 2 minutes of trying - any ideas?