Gas Gauge Malfunction
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Heel & Toe
Joined: Nov 2020
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Gas Gauge Malfunction
Hi guys,
I recently had a new fuel pump assembly installed in my 1996 LT1 vet. This cured the startup issue that I was having. However that fixed one problem and now I have an issue with the gas gauge reading on the dashboard. I will fill the gas tank to the top and will have a full tank of gas. The gas gauge will go down as I put the miles on. At a certain point the needle will show the tank is almost empty with the reserve light coming on. This usually meanings there's about 2 gallons or so left in the tank. I'll stop to fill up again and it will only take 10 gallons of gas to fill up to the top. Which means the tank was half empty when the gas gauge read almost empty. The mechanic can't figure out why. He said the float is working properly. I'm wondering if there needs to be some recalibrating of the gas gauge. Does anyone have any suggestions on what could be wrong with the gas gauge reading. Thanks. Rick
I recently had a new fuel pump assembly installed in my 1996 LT1 vet. This cured the startup issue that I was having. However that fixed one problem and now I have an issue with the gas gauge reading on the dashboard. I will fill the gas tank to the top and will have a full tank of gas. The gas gauge will go down as I put the miles on. At a certain point the needle will show the tank is almost empty with the reserve light coming on. This usually meanings there's about 2 gallons or so left in the tank. I'll stop to fill up again and it will only take 10 gallons of gas to fill up to the top. Which means the tank was half empty when the gas gauge read almost empty. The mechanic can't figure out why. He said the float is working properly. I'm wondering if there needs to be some recalibrating of the gas gauge. Does anyone have any suggestions on what could be wrong with the gas gauge reading. Thanks. Rick
Safety Car
Joined: Mar 2017
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From: LeClaire Iowa
Are you dead positive a 96 LT1 has a tank liner? When I did my fuel pump I was almost positive (at the time) that my tank did not have a liner. Dan
Melting Slicks
Joined: Apr 2019
Posts: 2,466
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From: Clark, NJ
If the pump was out before this problem it's most likely related. Maybe the float arm got bent? I'd slowly fill the tank with the key on/engine off, and watch the gas gage.
Or better yet, use your multi meter instead. The gage reading may be slower than the float rises so your gas gage isn't reading up and down on hills and turns.
I have a feeling you'll be removing the pump and float assembly. There's 4 t15 torx screws and the fuel door comes off. Remove the rubber water shield and you can get to everything easily.
Or better yet, use your multi meter instead. The gage reading may be slower than the float rises so your gas gage isn't reading up and down on hills and turns.
I have a feeling you'll be removing the pump and float assembly. There's 4 t15 torx screws and the fuel door comes off. Remove the rubber water shield and you can get to everything easily.
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Adding 10 gallons of fuel is not being sure there is 10 gallons of fuel still remaining in the tank.
The liner separates from the tank and keeps you from being able to fill to capacity. So if you have a liner that separates and you are showing 2 bars and you can only fill 10 gallons, the liner has displaced roughly 8 gallons.
There is no recalibration of the fuel pump assembly.
Melting Slicks
Joined: May 2019
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From: Mid-Atlantic
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Prior to replacing my fuel tank, the fuel gauge was reading about a quarter tank low.
The old tank had a bladder. New one doesn't. So I don't know if the float was catching on the bladder or what, but it reads on the money now.
I cut the tank into thirds when I was done with that job and the bladder was basically caved in on the back side of the tank (the side facing the front of the car)
The old tank had a bladder. New one doesn't. So I don't know if the float was catching on the bladder or what, but it reads on the money now.
I cut the tank into thirds when I was done with that job and the bladder was basically caved in on the back side of the tank (the side facing the front of the car)
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Joined: Mar 2017
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From: LeClaire Iowa
calibrate fuel sender float - CorvetteForum - Chevrolet Corvette Forum Discussion
I had to calibrate after CHANGING my float assembly. Dan
I had to calibrate after CHANGING my float assembly. Dan
Drifting
Joined: Jun 2013
Posts: 1,971
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From: Shell Point (Crawfordville) Florida
The coils in the fuel sender may have deposits on them interfering with the potentiometer readings feeding the gauge. Either remove it again and gently clean them off or put a container of Techron in the empty tank at the next fillup to try and get it clean. This is a common problem with the C4 and the C5 'vette and Techron is usually able to solve it.
Intermediate
Joined: Aug 2023
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From: Northern Virginia
2024 C4 of the Year Finalist - Unmodified
The coils in the fuel sender may have deposits on them interfering with the potentiometer readings feeding the gauge. Either remove it again and gently clean them off or put a container of Techron in the empty tank at the next fillup to try and get it clean. This is a common problem with the C4 and the C5 'vette and Techron is usually able to solve it.
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Joined: Jun 2010
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Did you not test the float arm actuation before install? If you are not seeing a reading below a half a tank, the arm is not dropping.
Safety Car
Joined: Jun 2010
Posts: 4,564
Likes: 1,677
The coils in the fuel sender may have deposits on them interfering with the potentiometer readings feeding the gauge. Either remove it again and gently clean them off or put a container of Techron in the empty tank at the next fillup to try and get it clean. This is a common problem with the C4 and the C5 'vette and Techron is usually able to solve it.
Safety Car
Joined: Jun 2010
Posts: 4,564
Likes: 1,677
calibrate fuel sender float - CorvetteForum - Chevrolet Corvette Forum Discussion
I had to calibrate after CHANGING my float assembly. Dan
I had to calibrate after CHANGING my float assembly. Dan
How exact is that calibration? Possibly bend/tweak it during install?
Safety Car
Joined: Mar 2017
Posts: 4,213
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From: LeClaire Iowa
I got very very lucky. If you read my last post in the thread the gauge is very accurate after the first bending. I actually thought I might have to do it a few times. Dan EDIT: I don't know how you would know how to bend it on the initial install without getting data on how it is reading stock.
Instructor
Joined: Mar 2022
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I bought a fuel pump/sender assembly from RockAuto and had to pull it and bend the arm 3 times before it was accurate. The problem is the pivot point on the new assembly is higher than the original, this throws off the sweep of the float as the fuel level rises and falls.
Intermediate
Joined: Aug 2023
Posts: 37
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From: Northern Virginia
2024 C4 of the Year Finalist - Unmodified
The new fuel pump was installed by the seller before I purchased the vehicle, so I don't really know how they tested it. What I know is they originally installed an aftermarket part, found that the fuel gauge was not working correctly, and replaced the aftermarket part with what they said was an OEM part.