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aleccesarenriquez
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This exact issue happened to me a while back. I had purchased a used fuel system and after install, we noticed the fuel hat had its pumps replaced at some point. The theory behind the issue was vacuum related (I don't remember the exact explanation, but it was something like the pump replacement prevented the hat from achieving proper vacuum to allow the fuel crossover to work how it should). I ended up selling back the fuel system to the original seller (super understanding dude), and I bought a new Fore system and have never had fueling issues since.
ChristianDev
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Hoping it’s not that. I re did the ground for the fuel pump plug hopefully that fixes it
ChristianDev
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I'm thinking one of my pumps may be bad. What's the best way to test both pumps? Unplug one and see if the other primes with the key on?
madballermintz
New Member
OP, wondering if you or anyone has resolved this issue. I'm just experiencing the same symptoms now... Fuel gauge consistent reads just over 3/4 tank when 'full.' Since pump is mechanical, assuming tank is actually full but reading is incorrect.
Ran out most of the fuel (10 miles to empty). Driver side fuel tank access seems to have plenty of fuel, passenger side is mostly dry.
Opened both fuel tank access points (under the rear seats)
-float seems unobstructed
-both sensors are reading correct ohms at empty and full
-using a stock fuel system
Any help would be appreciated!
Ran out most of the fuel (10 miles to empty). Driver side fuel tank access seems to have plenty of fuel, passenger side is mostly dry.
Opened both fuel tank access points (under the rear seats)
-float seems unobstructed
-both sensors are reading correct ohms at empty and full
-using a stock fuel system
Any help would be appreciated!
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Do you have a pump that can pull fuel from the other side of the tank like the stock pump can do? If you just throw any pumps in the tank it will only pull fuel from one side of the tank
madballermintz
New Member
Believe I am using a stock fuel system, although I can't say for sure as I bought the car used.
Understanding how that works may help me understand the issue. Should the passenger side be empty first? Or should they have equal amounts of fuel?
Does anyone know how I can tell if the system is stock?
I was also interested in the different "modes" of the fuel system. I was reading another thread where someone linked it, it appeared there was a way to adjust the system. Can't find it anymore...
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The stock pump has a Venturi on it which sucks fuel from the other side over to the pump side. The side with the pump should stay full until the other side is empty. There is a float that stops the Venturi from sucking air once there is no more fuel.
If the Venturi is no working or damaged or wrong pump the car will only be able to use around 3/4 of the tank
madballermintz
New Member
Don't believe that is the issue as the gauge reports 3/4 tank, but that is false. I've driven the car beyond the "0 miles to empty" readout and stull have gas in the tank...
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What is false?
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madballermintz
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You mentioned that if the pump is not working, I wouldn't have access to use 1/4 of the fuel in the tank. Even though the gauge reports 3/4 tank when I fill it up, it actually has a full tank. I've driven beyond empty (the car has stated) and there is still fuel to available to use.
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I think you misunderstood I was not saying that this is your problem. I was just answering this question and explaining how the system works
illtal
Well-Known Member
You need to find out if your Venturi is working correctly. This is the system that @Jackson1320 referring to. The active side pulls from the inactive side and it levels out naturally.
BangaRangStang
New Member
Any luck fixing the issue? Same fuel system, same exact problemWondering if you guys have any suggestions or tips or even happened to one of you guys. I currently have a Lethal performance fuel system with Dual 465's. Couple months after install I noticed the car will not fill up over 3/4's. Once it hits 3/4's the pumps stops like its full. If I keep trying to pump it eventually pukes it out. I pulled the hat and the floater is fine, not getting caught on anything. Any help is appreciated.
