This is in regards to a 2007 Ranger four wheel drive, V6 4 liter. There is nothing wrong with my fuel pump, I just have some general and maybe somewhat technical questions about the fuel pump. Per the attached picture of a generic but compatible pump, I have put red circles around the part in question. This being the large blue thing on the pump. I am wondering what it's purpose and function are on the pump. What does the blue thing do? How does it work?

 

Looks like the vapor valve, part of EVAP system

Like this one: https://lmr.com/item/LRS-9593B/2000-...nk-Vapor-Valve

Prevents liquid fuel from getting into the EVAP canister

 

well ron, per the link there, that valve looks like the one at the back end of the tank, for rollover protection and emission control. are you saying that the blue thing in my attachment, built onto the fuel pump has the same function and purpose?

in a recent modification, i accidentally put a vacuum cap on the larger (black) of the ports on top the pump, and when i tried to add fuel, their pump wouldnt continue filling. i figured it was because of the vacuum cap. so i removed it and it allowed the refill. that was the only modification done to the top of the pump. so would the blue thing in the pump, have an additional function?

 

The EVAP system captures gasoline fumes in the tank so they don't pollute outside air

When engine is off the Vent Valve(not the Blue thing) on the EVAPs charcoal canister opens to allow gasoline vapors to flow out of the gas tank THRU the Blue vent and THRU the charcoal in the canister(behind the gas tank), filtering the gas fumes out.

When engine is running vent valve closes and EVAP solenoid opens and use engine vacuum to suck gas fumes from the tank and canister to be burned in the engine.

The Blue container is a way to prevent liquid gasoline from flowing out a FULL gas tank and into the charcoal canister which would ruin it, so it is a VENT for that gas tank

If you cap this vent off then air/fumes can only get out via the filler tube, and if you are trying to put gasoline down the filler tube then you build up an air dam inside the gas tank, air can't get out so the gasoline can get in and it backs up the filler tube and shuts off the gas pump.

So you need to have a vent in the gas tank, and in your year that's the Blue thing

Now if you had the same problem of pump shutting off but hadn't cap off the vent then I would say your Vent valve on the charcoal canister had failed, it wasn't opening with engine off so air can't get out of the tank

 

okay. well i have removed all emissions related parts. including the related hoses connecting to the tank. actually, i left the other three connected; --two for fuel and the vapor hose connected to the filler tube. the back end of the tank had its hose removed as well. the cannister assembly is completely removed, as well as the two related solenoids. the intake manifold purge port is also closed with a vacuum cap.

per the attached picture, i then put one vacuum cap on the vent at the rear where the green circle is. then i put a vent hose on the larger port of the pump, per the red circle

the hose there on the pump has a sort of 'screen' on it to prevent contaminants from getting through and to breathe. so the hose there is 'open' to prevent the 'air dam' and allow gasoline to be added.

i would guess that since the port there on the pump is 'open', and that i dont have the cannister assembly, it shouldnt really matter that there is a cap at the end in the green circle.

i did previously have things backwards on those two areas on top. the blue thing was closed with a cap, and the area in green had the screen. but when i stopped to get fuel, the pump there didnt work. it kept stopping. i eventually went underneath and removed the cap from the blue port thing, and that allowed gasoline to enter. i later moved the screen thing to the area in red, and put the cap in the green area.

i wont need to refill for about another week, so we'll see how that goes with the green area being closed off now.

what do you think RonD?

 

As long as the gas tank is vented when engine is off you will be OK

Just get a Damp cloth and a hose
Remove gas cap
Wrap the hose with the cloth and put end of hose in filler with cloth around it to seal the filler opening

Blow into the hose, if you can blow into the tank then it is Vented OK, if you can't then its not vented

 

alright ron. your instruction here seemed similar to the eventual success at the station. the valve was open both times, same as it is now.

i used a long automotive rubber hose, and it actually fit into the filler hose quite snugly. it was big enough to be done without a cloth. even without the cloth, i was able to blow in, and it didnt seem plugged. since the vapor vent part of the filler hose is connected to the pump; when i blew, i could hear a slight hiss of air (with a faint scent of gasoline) coming from the two tiny slots surrounding the top of the filler pipe by the cap. so, it seems the vapor aspect is still working.

and, per this operation, it seems that the 'valve' in the green area of the picture, and research ive done, is attributed to a rollover protection. outside the quite unlikely event of a wreck and the truck flipping over, i would guess that that rollover valve, doesnt really serve a purpose now. especially not being connected to any canister. --is the rollover thing correct for that valve in the green area? --rollover protection and vapor vent

 

Yes, the gas tank should be self sealing in the event it is on its side or upside down, i.e. roll over

Don't want gasoline dripping out feeding a fire

So any vent on the top should be self sealing
Fuel lines are a different story, lol, fuel pump's inertia switch should shut down the fuel pump power but check valve in pump could let some fuel leak out of a broke fuel line

 

okay well the 'rollover-vent' in the green circle has a vacuum cap, so its 'permanently' closed. in the event the tank is upside down, would the vent i talked about here in the red circle close like you are saying, or would it be open, spilling fuel where i connected the short hose with a 'screen'?

and then, with how things are set now, should i expect there to be any "whoosh" sound from opening the fuel cap? i have tested that after different periods of driving and not had any rush of vapor or air.

 

No "whoosh" if you have disabled the vacuum supply from the engine

The EVAP system would hold vacuum just after shut down to continue pulling any vapor from the tank thru the charcoal canister
And that causes the whoosh when you open gas cap just after shutting down the engine

The vents in the tank also prevent Over filling, if they didn't you could just keep pumping in gasoline thru the filler as it came out the vents
So there is some kind of a valve that allows air out but prevents fluid from flowing out

 

alright then Ron. thank you for your input here.