Newbie with a question.... shocking, huh?

[joeschwartz5150]

So I'm driving up the 101 fwy. about 4:30a.m. in my '99 Ford Explorer. There is a sudden loud pop and within a moment or two my car has shut down and is rolling to a stop. I make it to the end of the off-ramp and smell gas. I get out to check whats happened, and the full tank I purchased is emptying itself from an as of yet undiscovered location. Once I am in a safe place to do so, I crawl underneath and find that the front (going to intake side) of the fuel filter's hose has popped off. I reconnect it, walk to get gas in a can, return, place the gas in to the tank drive home and all is seemingly okay. Later that day I go to fill the tank, which I had just done the day before, and notice the flap where you insert the gas pumps nozzle inside the fuel filler area is bulging out. So now instead of a lazy mechanic installing the fuel filter inadequately I'm thinking excessive fuel pressure popped of the previously mentioned hose and bulged out this flap. Anyone who might be able to tell me what would cause excessive fuel pressure? Am I totally off in my diagnosis, could it be something other than excessive fuel pressure? Any and all help is appreciated!

BTW, The Check Engine Light does come on for 2 seconds at start-up but does not stay on. So no codes are present. I do not have a fuel pressure gauge but I am working on getting one to use though. The gas cap has not been replaced. The only thing that I've had replaced in the past three months (when I purchased the vehicle) is an O2 sensor that was needed to pass smog certification.

Respectfully,

Joe Schwartz

 

[lobo411]

Am I totally off in my diagnosis, could it be something other than excessive fuel pressure? Any and all help is appreciated!

No idea, but fuel filters are cheap and easy enough to replace that I'd just give it a whirl. Who knows...you might get lucky and end up with nothing more than a bad filter.

 

[lil'mounty]

Something capable of doing what you described, would require a large amount of instantaneous force/pressure in the gas tank. (think about that for awhile...)
Ignition of the fuel vapors in the tank would create that and your loud POP, but wouldn't it ignite the gas? NOT NECESSARILY! I have been hearing more and more stories of our current gas quality being so poor it now has horrible flash points.
One first hand experience was a body shop owner torching a section of fender and accidentally cutting through the fuel fill hose, inches above the gas level (full tank) and it never ignited. WITH AN OXY TORCH!!!
Not saying that's what happened but it is what you are describing and what would cause the vapor to ignite is unknown to me.

 

[deweyville65]

Something capable of doing what you described, would require a large amount of instantaneous force/pressure in the gas tank. (think about that for awhile...)
Ignition of the fuel vapors in the tank would create that and your loud POP, but wouldn't it ignite the gas? NOT NECESSARILY! I have been hearing more and more stories of our current gas quality being so poor it now has horrible flash points.
One first hand experience was a body shop owner torching a section of fender and accidentally cutting through the fuel fill hose, inches above the gas level (full tank) and it never ignited. WITH AN OXY TORCH!!!
Not saying that's what happened but it is what you are describing and what would cause the vapor to ignite is unknown to me.

Wouldn't need instantaneous pressure. Prolonged pressure would do the same thing. Think full tank, vehicle sitting in the hot sun all day. Not very likely, but possible. I would think the fuel pressure regulator is faulty, causing excess pressure which could blow off the fuel line. However, I would think with the ignition/pump shut off, not all the gas would leak out. And, where does it say the fuel ignited?

 

[lil'mounty]

The gas fill flap is not a tight fit, it is vented, the force would have to be instantaneous to "bulge it out" or deform it.
Nobody said the gas ignited, that's the point, it would need more air to do that, so thankfully it was a full tank.
I believe if his ignition key is on, it will continue to dump fuel on the ground.
Your thoughts are correct as far as a hot day, but I don't know how bright the sun is at 4:30 AM and I am under the assumption he just filled the tank, so all pressure from the day before would have been relieved.
I think we need more input from the O.P.
-How loud was this pop, and from where?
-Is the gas flap actually deformed?
-Is heat a possibility?

 

[Robman]

Do you always use that gas station/grade of fuel ?

Gas these days has an ethanol blend which actually boosts the octane rating once blended with the regular fuel. If there is water in the tank of the gas station, and it gets filled up with fuel, the ethanol/gasoline blend has been known to "Phase Separate" ... meaning the gas and ethanol separate. The existing water in the tank actually drags the ethanol out of the gas and then sits at the bottom of the tank. Leaving you with a lesser octane fuel and most of the ethanol at the bottom. Now given that the suction stub of a pumping station or STP ( suction turbine pump) found in more modern gas stations with " dispensors" that you fill your vehicle out of, sit roughly 6-8 inches from the bottom of the tank. You can begin to understand the things that can take place from there.