amos1027

I have a 2010 F150, after putting gas in the tank the gauge will only read 3/4 full. The digital gauge will function properly for a while then start to lose 3-4 miles loss for every mile driven. Just put in the shop and the mechanic replaced the fuel pump and fuel sensor. After driving today the same thing happens. Also to be noted is after putting gas into it the truck will not start, takes a few attempts and sometimes can hear a vacuum being pulled into the tank after driving a while. Any suggestions would be appreciated.

BLS

Bad tank ground maybe?

amos1027

I hadn't thought of that, but I will tell the mechanic to look into that. Would the pressure/vent valve on the tank have anything to do with it?

BLS

Sorry, I don't know that one. Your truck's a little too new for me. Sounds reasonable though. A hissing sound (and everything else) would probably make me wonder about the pressure vent valve too.

Anyway, I was just thinking it might be a ground problem (at the tank or battery/battery cables or...) because it could interfere with your digital gauge as well as your fuel pump. (causing your temporary no starts) Oh also, if it is a ground problem you can replace the fuel pump all day and it's not going to help. New pump or old... no ground, no pump. I'm just saying.

Wish I could help. Hopefully someone who knows more will kick in here.