Gas gauge problem '99 F150
Occasionally, when I fill my truck up, the gas gauge does not register until I take the gas cap off and put it back on. Today, that did not work but after 15 minutes it finally read a full tank. I use a locking gas cap and the check engine light is NOT on. Also, my truck has never been under a quarter tank, ever. 1999 with 44,000 miles. Any ideas?