I only know 2 things about Coalinga--
1. It was the epicenter of an earthquake (maybe 10-15 years ago?). Did some real damage there; was felt all the way to Los Angeles.
2. The name is derived from "Coaling A". During the coal-fired railroad days, they replenished their coal at "coaling stations". This one was designated as station "A" -- so when the town formed, they named it Coalinga.

Well, it's useless information, but now you know.