Well, a problem I have been having for a few months took a turn for the worst yesterday. Ever since I got my car, every once in awhile, my fuel gauge becomes erratic, showing I have 2 miles till E, or 20 miles etc, and then going back up to half full or 2/3's full, or whatever the tank is REALLY at. However, yesterday, the Fuel gauge stayed at 2 miles to E, and then zero. I knew this wasn't possible, as I had just put in 10 gallons. I was under the impression that just because the fuel gauge is reading off, gas is still getting to my engine...APPARENTLY THIS ISN'T THE CASE.

As this was happening, my car began to "buck" like it was actually RUNNING OUT OF GAS. I looked at my fuel pressure gauge, and sure enough it was blinking red at me, extremely low fuel pressure. I costed off the the interstate, I couldn't believe it. I tried restarting my car multiple times...NOTHING...I cranked and cranked, I KNEW there was no way my tank was empty, and it wasn't! I had to have my girlfriend bring me 3 gallons of gas. When this happened, my fuel gauge went back to normal, it put me at about 3/4's of a tank. Someone please tell me how in the world this is possible. I have dual GT pumps, and 42lb/hr injectors.

I am completely paranoid at this point to have anything less than 3/4's of a tank in my car now. Now, this has never happened to this extreme before. My fuel gauge has been erratic before, but not to this level, and I sure as HELL didn't think my engine would actually "think" their wasn't enough fuel left.

Any help is appreciated, thanks guys.

 

It's a saddle tank. Maybe half the tank is not working properly.

 

Can you elaborate alittle more for me please? Thanks!

 

A little, but not much. Fuel systems are not my strong point.

The tank is a dual-container (saddle type), with each half equipped with a fuel level sensor. I think that one of the containers is used first, and then the other container is used.

The clue you gave was that adding three gallons of fuel brought the fuel gauge up to about 3/4 tank. That would mean you were at approximately 1/2 tank before adding the additional fuel. So I was just wondering whether maybe one of the containers was not working properly.

 

from what i'm reading, it sounds like an issue with the
drivers side fuel level sender.

each side of the tank has a fuel level sender.

the passenger side is responsible for the readings you see on the fuel
gauge between 1/2 and full.

the drivers side is responsible for empty to 1/2.

 

I would start by checking all of your wiring connections. Most of them are disturbed when installing the fuel pumps.

 

This makes complete sense, thanks hammeron...Any idea on fix cost?

 

I had this same problem. Not sure if the hesitation/bucking is related to the fuel level gauge though. There is a problem with the sending units and I had both of mine replaced (paid by Ford) and they also recommended using Techron to clean the sending units, and removing moisture and other crap from the fuel tank. I would try a bottle or 2 of Techron before paying for any service though, unless it's under warranty. I had my fuel tank sending units replaced while my car was under warranty, but Ford had the service bulletin attached to my service receipt along with the recommendation to continue to use Techron once in a while to keep the new sending units clean and working properly. I haven't had that problem with the erratic sensor since, and it's been over 2 years.

 

yeah try the techron like Doc recommends. if the car is
out of warranty, then you can pretty easily replace the
fuel sender at home if you have the time.