Fuel Pump must be bad

[Ted Best 2]

I swapped out the Fuel Pump Relay and it still won't start if the temperature gets warm. So i'm assuming it must be the Fuel Pump. if i turn the key when it's warm i don't hear the fuel pump. can anyone explain why it's only affecting the pump when it's warm?



Also can anyone refer me to a good site/brand for Fuel Pumps? They seem to range in price a lot. is there really a difference?



Thanks

 

[JohnPenny Peluso]

Have you verified that the computer is sending a signal to set the relay?

 

[Ted Best 2]

how do i do that? would the heat affect that? i'm very confused at why it only happens when it gets warm out

 

[Conrad AlbertoJr]

My dads explorer is having the same problem. I did the voltage check to the harness and it looks ok. Im leaning more toward the fuel pump as well. Exact same symptoms.

 

[Gary Hart]

I just now had this problem.... for me I noticed the tube which vents air-pressure from the valve-cover area back into the air-intake boot becomes very loose in this hot weather. Mine didn't have any hose-clamp or anything on it and you could tell it would suck-in outside air!



I noticed this because I checked my air-filter annd the tugging on the boot made that tube slip-out so when I snapped the air-filter back in place "Whoa!" this gaping hole of that tube looking me in the face. Upon trying to push it back into the air-boot and thhe little rubber albow coming off (what I'm calling/assumingn is) the valve-cover area.. I noted that it didn't seat positively.. ANd... that it slid in and out super easily.



I was at Harbor Frieght when she decided to pull these shenanigans on me... so I went back inside and bought some ZipTies and zip-tied those hoses to that connecting tube.... 2 more start attempts and BadaBing! On that 2nd one.. she lit up. And now she's idling slightly better than she was before. :banana:

 

[Yardsale]

There is a known problem or defect with some Ford fuel pumps. The check valve in the fuel pump assembly begins to fail. Short story - this check valve maintains fuel system pressure when the vehicle is not "on". When it fails, and it is hot enough (combination of engine heat and ambient temperature), and enough time has elapsed, the system will vapor lock as the pressure bleeds to the tank. As more time to elapses, the fuel vapor will condense back to fluid.



Why won't the pump push fuel to through the system? Because on some vehicle models, the fuel pump runs for only a set time (something like 10 seconds) initially and that is not enough time to push the vapor through the system.



Work around: Turn the key to the "On" position (until the fuel pump runs) and wait about 20 seconds, turn the to the "Off" position for about 10 seconds. Repeat this three to five times and the vapor should push through the system.



I read where you don't hear the fuel pump. This MAY be because there is pressure in the system, so the pump won't run (there is pressure in the system but the pump hasnt run long enough to push the vapor through to the tank).



Try the workaround; see if it works for you.