Bad Fuel Economy

[Brad B]

Could be needing a new fuel pump. My mileage went to $#% when I replaced mine. Well actually, just before. Is it leaking ?

 

[DOC-MX]

So you think that a leak in the valley could really down the milage by itself? and when you chang the fuel pump, increase the milage?
BTW when you change the fuel pump you have to get out the FPR SHIM?

 

[95_stroker]

Im thinking if you are leaking enough fuel into the valley to cause a significant drop in MPG that the underside of the truck should be slick with fuel back to the rear differential and she should REALLY mark her spot when you shut it down.

 

[Brad B]

That's what mine did. Milage dropped by almost half. I'm sure there are some smarter folks who could tell us exactly how much fuel can be run out of the weep hole at a certain pressure. All I know is after I slapped a new pump on, my milage went back to it's wonderfull and reliable 15 mpg.

And I don't have a shimmed FPR but you shouldn't have to mess with it unless you're going to replace your FPR and or the filter bowl assembly. Which BTW I had to do at that same time.!! Though I'd be smart and clean that "little but of grime" out of my bowl....ended up pushing a hole right out the bottom. Good thing I found out that way rather than spewing fuel all over the city like I did when my last bowl went bad !!

 

[DOC-MX]

Im thinking if you are leaking enough fuel into the valley to cause a significant drop in MPG that the underside of the truck should be slick with fuel back to the rear differential and she should REALLY mark her spot when you shut it down.

No the underside of the truck is not slick with fuel and only marks a little spot in the driveway when is shut down. but the MPG has dropped to 11
so maybe some body knows how much fuel can be run out of the weep hole at a certain pressure. Anyway Im going to change the fuel pump, hoses, etc ASAP.

Ok, about the FPR shim, understood.

Thanks

 

[97PowerSmokerIA]

well im gettin arount 10 MPG but im now havin a bigger problem when i start my truck cold it starts great but once up to operating temp and turned off while trying to restart the truck turns over for a good 20 sec then starts to chug and will then stall unless i hold the starter on until the truck fully starts but once running it sounds great i called the Ford dealer and they said it might be a wiring harness behind my engine or quite possibly a high pressure oil hose leaking but my oil levels fine and theres no oil leak........plz help

 

[MBRPCrazyford]

10 MPG?? Did you check the feuel pump yet??