Fuel Sending unit
07-04-2015, 05:02 PM
#1
Cruising
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Fuel Sending unit
Hi All
I'm having problems with my fuel gauge on my 72 T-top. Everything posted seems to deal with other problems with the fuel gauge. I have done some diagnosis and cleaned the grounds and such, but still the same symptom. The problem I am having is when the tank is full it reads full, but when the tank is half full it reads empty. I put 11 gallons in it (over 1/2 tank) and it reads just below one quarter of a tank. My sending unit seems to come out the bottom of the tank although I haven't actually taken it out yet. Was this right for a 1972? I'm thinking it's the sending unit since that looks old & rusty, but the tank has been replaced before and is fairly new. Does anyone have some input & direction to help me with this problem?
Thanks
I'm having problems with my fuel gauge on my 72 T-top. Everything posted seems to deal with other problems with the fuel gauge. I have done some diagnosis and cleaned the grounds and such, but still the same symptom. The problem I am having is when the tank is full it reads full, but when the tank is half full it reads empty. I put 11 gallons in it (over 1/2 tank) and it reads just below one quarter of a tank. My sending unit seems to come out the bottom of the tank although I haven't actually taken it out yet. Was this right for a 1972? I'm thinking it's the sending unit since that looks old & rusty, but the tank has been replaced before and is fairly new. Does anyone have some input & direction to help me with this problem?
Thanks
Last edited by mmoore289; 07-04-2015 at 05:04 PM.
07-04-2015, 07:05 PM
#2
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Hi mm,
Have you looked into the tank to determine if the 'float' is indeed on the surface of the gas (not partially submerged) and that the thin 'arm' it attaches to is free to travel through it's complete arc?
Yes, the sending unit does come out of the bottom of the tank.
There's a 'flanged' ring that must be turned to release the sender from the tank.
The tank should be as close to empty as possible and you should be prepared to deal with what ever fuel may come out through the sender's hole.
Regards,
Alan
Here's the sender (no locking ring or rubber gasket) laying on it's side not as it's positioned how it sits in the tank.
The arm attaches to the rheostat at one end and the tubular float at the other.
Have you looked into the tank to determine if the 'float' is indeed on the surface of the gas (not partially submerged) and that the thin 'arm' it attaches to is free to travel through it's complete arc?
Yes, the sending unit does come out of the bottom of the tank.
There's a 'flanged' ring that must be turned to release the sender from the tank.
The tank should be as close to empty as possible and you should be prepared to deal with what ever fuel may come out through the sender's hole.
Regards,
Alan
Here's the sender (no locking ring or rubber gasket) laying on it's side not as it's positioned how it sits in the tank.
The arm attaches to the rheostat at one end and the tubular float at the other.
Last edited by Alan 71; 07-04-2015 at 07:45 PM.
07-04-2015, 07:15 PM
#3
Melting Slicks
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Hi All
I'm having problems with my fuel gauge on my 72 T-top. Everything posted seems to deal with other problems with the fuel gauge. I have done some diagnosis and cleaned the grounds and such, but still the same symptom. The problem I am having is when the tank is full it reads full, but when the tank is half full it reads empty. I put 11 gallons in it (over 1/2 tank) and it reads just below one quarter of a tank. My sending unit seems to come out the bottom of the tank although I haven't actually taken it out yet. Was this right for a 1972? I'm thinking it's the sending unit since that looks old & rusty, but the tank has been replaced before and is fairly new. Does anyone have some input & direction to help me with this problem?
Thanks
I'm having problems with my fuel gauge on my 72 T-top. Everything posted seems to deal with other problems with the fuel gauge. I have done some diagnosis and cleaned the grounds and such, but still the same symptom. The problem I am having is when the tank is full it reads full, but when the tank is half full it reads empty. I put 11 gallons in it (over 1/2 tank) and it reads just below one quarter of a tank. My sending unit seems to come out the bottom of the tank although I haven't actually taken it out yet. Was this right for a 1972? I'm thinking it's the sending unit since that looks old & rusty, but the tank has been replaced before and is fairly new. Does anyone have some input & direction to help me with this problem?
Thanks
My '72 is just like yours. When the tank is FULL it reads FULL but reads EMPTY when I still have 7 gallons in it. That can be adjusted by bending the float arm so it'll read more accurately. I actually prefer to have it read EMPTY when I still have 7 gallons in it because I know it'll go a LONG way after it reads EMPTY.
07-04-2015, 07:41 PM
#4
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My '72 is just like yours. When the tank is FULL it reads FULL but reads EMPTY when I still have 7 gallons in it. That can be adjusted by bending the float arm so it'll read more accurately. I actually prefer to have it read EMPTY when I still have 7 gallons in it because I know it'll go a LONG way after it reads EMPTY.
07-04-2015, 07:56 PM
#5
Former Vendor
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
All tanks 68-74 have the sender on the bottom.
I agree with above, it sounds like a sender issue. Pull the sender out and do a ohm reading test. 0 is emply and 90 is full. If you are trying to tweak the 1/2 tank you'll have to do this by estimating the 1/2 tank and tweak the arm a bit.
There's a bunch of info on our repair page about your sender at this link
Willcox Repair, Help and Installation
1972 related fuel gauge items are here
Willcox Corvette 1968-1976 Corvette Fuel Gauge and Sending Unit Testing
If you can't figure it out or need help post again.
Willcox
I agree with above, it sounds like a sender issue. Pull the sender out and do a ohm reading test. 0 is emply and 90 is full. If you are trying to tweak the 1/2 tank you'll have to do this by estimating the 1/2 tank and tweak the arm a bit.
There's a bunch of info on our repair page about your sender at this link
Willcox Repair, Help and Installation
1972 related fuel gauge items are here
Willcox Corvette 1968-1976 Corvette Fuel Gauge and Sending Unit Testing
If you can't figure it out or need help post again.
Willcox