savage ... 1/20/2018
2007 Mercury Mountaineer Base 6 Cyl 4.00L
gas gauge delayed reading
engine is a v-6 4.0 sohc, Most of the time when I put gas in the truck it takes forever for both the digital gas gauge to register and the normal gauge to register that the gas has been put in. Many times it will go up once making me think I've been ripped off on gas and sometimes it will go up at 2 different times till proper gas amount is finally registered. What would cause this, it's extremely fustrating and nerve-racking!!
I would say the most likely cause is a failing fuel sending unit ( MOTORCRAFT PS257) These are located in the fuel tank and are a part of the fuel pump and housing assy ( MOTORCRAFT PFS381). That being said there is an outside chance it is a wiring harness problem, I would suggest a good repair manual with wiring guide and perform the listed Ohm test on the sender before pulling tank. Hope this helps.