If, when you are in FSX and you are switching from one 3rd party addon aircraft to the CS C-130, this can cause problems. I always go from one 3rd party addon to another, by loading the default C172 in between. Like this:

Other 3rd party addon is loaded into FSX.
ALT > Aircraft > Select Aircraft > C172
After it has loaded into FSX, I set in a cold-n-dark setting. Then I check and make sure that the fuel tank selector is set to ALL.
ALT > Aircraft > Select Aircraft > CS C-130
The C-130 should work fine after doing that.