To get the diesel smell out of clothes fill a bucket of warm water with some degreaser such as Purple Power cleaner and then allow the clothes to soak in the degreaser overnight.
Then after pour a cup of degreaser again into the washing machine and add the clothes and wash the clothes like normal.
The diesel smell should then be out of the clothes as this is what I do myself when I get diesel on my clothes and the diesel smell needs to come out.
If that doesn't work then mix some baking soda in with the water as well as some vinegar and allow it to sit again preferably overnight.