Sounds like you have an air intrusion problem causing fuel to drain back when it sits for any length of time. The most common cause of this is bad fuel return lines (pipes that run between the fuel injectors). Fitting a new return line kit usually solves the problem.
Another cause could be bad glowplugs. How long does your Wait To Start light stay on? When cold should be around 10-15secs. Less than that and you could have one or more bad glowplugs.
Use as little ether as possible, easy to break piston rings on these engines.