I just got my new 2009 F150 XLyesterday and after 100 miles today the message center has started to read Check Fuel, Fill Inlet. Can someone please tell me what this meens.

 

tighten your gas cap?

 

There is no gas cap on the 09's!!

 

hoozamahjiggamahwhat?!?!?! I'll have to drive over to my granpdas and take a gander at his. How does it keep the gas tank pressurized?

 

It's true - When I was taking delivery of my '09 FX4 SuperCrew the sales guy made a point of showing me that there is no gas cap.

 

is it different in any way or would it be the same as taking the gas cap off of an 08 f150 and throwing it out? besides of course the computer flippin out

 

I didn't bother asking the salesman how it worked, but I would imagine that Ford did one of two things:
1) integrated a check valve type of solution within the fill neck to maintain pressure when you don't have the pump nozzle inserted, or
2) redesigned the system significantly to eliminate any need to maintain any type of pressure within the tank

I am guessing that throwing away the gas cap from an 08 F150 doesn't cause either of those two options to magically appear on the 08 - so yes, the computer would flip out.

Note that even though the '09s don't require a gas cap - Ford will be more than happy to sell you a locking gas plug for $19.99 (in case you need that kind of security)

 

a pressurized tank does'nt sound right, i can see the fuel lines being pressurized but why the whole tank? when you turned on the key you can hear the pump kick in then stop after a second or 2, not enuff time to pressurize the whole tank, that would take several minutes. i'd think that would be like riding a time bomb. how much pressure are we talking about?

 

the fuel tank is not pressurized. there is a MAP sensor close to the tank to insure that there is always a negative pressure in the tank to keep the fumes in the tank and not in the atmosphere. there are check valves and sensors to insure that the tank stays slightly under normal outside pressure, this system is called the enhanced evaporative emissions system or EVAP system. so, if there is a leak meaning the fuelcap or the new fangled capless inlet has a leak the sensor tells the computer that theres to much air going into the tank and you get the fueldoor light. i got this info from AUTOINC a online auto repair forum, i says its a misconception that intank fuel pump pressurizes the tank,this make more sense to me. now does anyone have anything else to add? i'm just reading what the article says. it just does'nt make any sense to pressurize the tank when the pump is pushing fuel out of the tank to pressurize the lines, how would it get pressurized?

 

you might look at the little flapper thingy in the inlet and make sure its closed, stick your finger in there and if it moves open then its not locked, there are buttons on either side of the inlet that release the flapper thingy when you insert the nozzel at the gas pump, maybe you pulled out to fast or too slow and it did'nt seal right, try that and then take it to the dealer and get it checked out even if that fixes it.

 

Sorry for any confusion I might have introduced by using the term 'pressurized' very loosely - my engineering head considers a vacuum and a negative pressure to basically be the same thing.

I guess the main point for the gas cap vs no gas cap discussion is that up through '08 model year there is a dependency on having a sealed system with the gas cap serving as an integral part of maintaining that seal.

Bottom line, if you aren't driving an '09 - don't just throw out your gas cap!

 

Sometimes the "gascap" won't seal or cause a vent problem, and cause your truck to throw a code like O2 sensor reading different mixture or something like that. May even cause it to run rough. Had that problem with an 2009 5.4 and had to get a new "cap" from Ford. I have also heard that there is another vent at the bottom of the tank or someplace like that. Worst part; there is no change up kits to get a real gascap for these trucks (in Canada anyway).

 

Lol My point being about that bottom or other vent is that it gets plugged with road grime and other crap that could cause a vent problem as well

 

Considering this thread started in April 2009... I would hope the issue is resolved by now.