with the fule cap off, try to start up again.

Don't look for a vent hole in these fuel caps... these cars have a vacuum reliefe system that could be clogged. The air intake for this system on your car is probably on the left side under one of the doors. It's easy to see. If it needs cleaning, you can hook on a length of clear vinyl tubing into which you pore some diesel purge or other cleaner and then use compressed air to force this back through the line and relief valve to clean things up.

Sam