Dark Stone

I know what that is. There's a breather valve on your gas tank. It's there to allow air to be pushed out when you put gas in and to let air in when your engine pumps gas out. It's a ball valve. If you truck flips upside down the valve will close and prevent gas from running out. If that valve is stuck shut, you will have problems getting gas in because the air in the tank has nowhere to go but back up the filler neck which shuts off the pump. When the truck runs it will have trouble pumping gas from the tank (try pouring gas from a can without the second opening being open. Same thing) This can come and go as the valve opens and shuts as you hit bumps causing you check engine light to go on and off as well. I don't know where the valve is on the f150 but changing it usually involves dropping the gas tank anyway. The part isn't too expensive though. You can also take the bed off your truck and get to it that way. That might actually be easier since I'm assuming you don't have access to a lift. Just 6 bolts and a couple of buddies gets that done.


John

princejo

Does gelatin set up in gasoline?

My first instinct was that they stole your catalytic converter. Did you our your mechanic look for that?

When all else fails go to Schucks / Checker and borrow and OBD II and pull the codes.

Buck

Hahaha Im pretty sure he'd notice if they had stolen his Catalytic converter/s

Mod (Ret.)

You mentioned that you "reset the terminal" to clear the trouble code you had (the check engine light and code was set due to a loose gas cap; happens alot when folks forget to turn the cap until it "clicks"). Not sure what you mean by this (I have always disconnected the battery after repairing the faulty component to clear codes). In any event, your ECM may be stuck in a "closed loop" mode, or it may have to "re-learn".

Ask a Ford service rep. Explain what happened to you that night (gas cap loose, etc.) and get their expert opinion. Also let them know what you did to reset the code.

As to the possibility of sugar in the tank, you'd have other problems by now; sugar is a fine granular substance that can score the cylinder walls and cause oil burning (oil can get past the oil ring). You would have seen the sugar around the fuel opening; if you did not notice this, put this out of your mind. I doubt a bunch of punk kids carried a funnel and a bag of sugar just to be mischeavious; most are just too stupid or strung out on whatever the drug of the month is to be smart enough to use a funnel and pour in sugar to cover their tracks. Even after a few days before you descovered the loose gas cap, you would have seen the loose sugar around the opening of the gas spout.

Getting back to your poor mileage, ask a Ford rep if it takes awhile for the ECM to "re-learn" the driving habits. Perhaps Ford does not have this type of ECM; but most cars do these days. At the very least, they can assist you as to why the mileage seems to be low after this incident.

Post your results; I'm courious as to this condition myself now.

iRmARK88

I think i'm still in possession on my converters lol

but sounds like i might have to replace that ball valve if this problem keeps up.

i've put the sugar out of my mind cuz like you said there was no sugar around the cap...

to reset the code i took off the negative battery terminal and let it chill for about ten minutes. what you're saying Bucko makes a lot of sense. like i said earlier, i have to drive it a bit more to see what the MPG is doin now since i've flushed out the tank with new/different brand of gas. if my truck is stuck in "closed-loop" mode how would i get the system out of that mode??

roryh23

did you look to see if they drilled holes in your tank?

Good old Bill

No help here with the poor mileage, as I remember the fill pipes, its two hoses, one small to vent while filling and the larger fill pipe. Perhaps during the siphoning process the inner small hose came off and is now obstructing the fill process.

Mod (Ret.)

It would only be in a "closed loop" mode if there was still a failure in your ECM that affected drivability (I.E. the mass air flow sensor fails, or an O2 fails). In "closed loop", the ECM is in a "limp home" mode, meaning the air to fuel ratio is fixed, and no longer adjusting itself based on various inputs from the engine sensors (O2's, mass air flow, etc).

I doubt you are in a "closed loop" mode, as the truck would feel like it has no power (as compared to your driving before).

Weldman0730

The sugar dissolves in gas, it wont mess the engine, so even if they did put sugar in it you would be fine, I wached the mythbusters try this trick.

As for the kids, my guess was they were trying to siphon gas, most kids dont go around to try to mess stuff up, they were just trying to siphon, especially if you still have your cat. Either way someone needs to put thier boot to those kids asses. I caught a couple kids siphoning gas out of my 94' F150, so chased them away and poured the gas back into the truck.

I would check and make sure there are no holes in the actual tank, the dumb kids may have punched a hole, because there is a screen to stop sphiphoning.

jhunt47

i have seen when sugar gets put in the tank it clogged up the plastic screen on the fill hose and prevented fuel from being put in and also made the truck run bad i had to drop the tank and clean it and also the sock filter on the bottom of the pump was clogged and replaced the fuel filter and blew out the lines from tank to the fuel rail do not rule out sugar i would take it to a ford dealer and have this looked at