• Welcome to For E Bodies Only !

    We are a community of Plymouth Cuda and Dodge Challenger owners. Join now! Its Free!

Fuel Sending Unit

money pit

Well-Known Member
Joined
Nov 17, 2017
Messages
447
Reaction score
44
I'm tired of replacing the aftermarket sending units and trying the different grounding fixes. I tried everything and my fuel level is still way off. Does anyone know where I can get an NOS sending unit? I heard they are pricy but it may be worth it. Any thoughts? Thanks
 
Last edited:

moparleo

Well-Known Member
Joined
Oct 17, 2011
Messages
6,358
Reaction score
1,291
Location
So. Cal. Riverside area Moreno Valley
No guarantee they will be accurate either. There are videos on calibration, but the old float style will never be accurate like modern units are. Very old technology. Just a rheostat type.
 

EW1BH27

Well-Known Member
Joined
Dec 31, 2021
Messages
89
Reaction score
46
Location
Canada
There's some info in this thread that may help. My rheostat is perfect through the whole sweep but the gauge is off by about 1/8 of a tank. That's just a matter of me getting around to bending the arm with the float on it.

 

money pit

Well-Known Member
Joined
Nov 17, 2017
Messages
447
Reaction score
44
No guarantee they will be accurate either. There are videos on calibration, but the old float style will never be accurate like modern units are. Very old technology. Just a rheostat type.
I don't think its a matter of calibration. I can fill the tank, it will read full for a few miles, drop to a 1/4, go back up to 3/4, go to zero. Its a similar situation I had with with the neutral safety switch. I went through 2 aftermarket switches and after reading a thread on this site, I switched to a NOS. Problem solved. I read a thread also on this and another site, where they had the same problem until they went to a NOS sending unit. Thanks.
 

money pit

Well-Known Member
Joined
Nov 17, 2017
Messages
447
Reaction score
44
There's some info in this thread that may help. My rheostat is perfect through the whole sweep but the gauge is off by about 1/8 of a tank. That's just a matter of me getting around to bending the arm with the float on it.

My fuel level is all over the place while I'm driving.
 

Juan Veldez

Well-Known Member
Joined
Jan 1, 2011
Messages
515
Reaction score
115
Location
Nor Cal
Not sure if this matters for your issue, but do you have the grounding strap that jumps the rubber fuel line at the tank installed?
 

money pit

Well-Known Member
Joined
Nov 17, 2017
Messages
447
Reaction score
44
Not sure if this matters for your issue, but do you have the grounding strap that jumps the rubber fuel line at the tank installed?
I grounded the sending unit directly to the battery. I think I'm on my third sending unit.
 

Wayne75129

New Member
Joined
Aug 30, 2022
Messages
2
Reaction score
0
Location
Winnipeg Manitoba
I think the straps on the gas tank are part of the ground . i believe i sanded them down to make good contact. I know theres a stud for the ground wire but the straps are part of the ground
 

73Dodge

Member
Joined
Dec 8, 2020
Messages
15
Reaction score
7
Location
USA
Check the float arm for side to side play as well. I had a pricey aftermarket unit that was supposed to be "premium" with so much play, it was grounding to the pick up and causing very erratic readings. Bending the arm out fixed it but in the end I went with a $30 3/8 pick up from Vans and it's been very reliable. In case you do want to go aftermarket, I run Speedhut gauges and the fuel gauge can be calibrated to the individual sender, not just the typical mopar range. I get accurate readings and the needle doesn't bounce around hardly at all.
 

money pit

Well-Known Member
Joined
Nov 17, 2017
Messages
447
Reaction score
44
Remove the sending unit and test it before you start buying a bunch of parts. They are a very simple mechanism and it could just be a poor connection causing the wide fluctuations and might be repairable.
I tested the sending unit outside of the tank. It worked well. Read empty, 1/4, 1/2, full when I actuated it. When I placed it in the tank, it read 1/4 with the tank full. I read a couple of threads on this site that had the same experience. Thanks
 

money pit

Well-Known Member
Joined
Nov 17, 2017
Messages
447
Reaction score
44
Check the float arm for side to side play as well. I had a pricey aftermarket unit that was supposed to be "premium" with so much play, it was grounding to the pick up and causing very erratic readings. Bending the arm out fixed it but in the end I went with a $30 3/8 pick up from Vans and it's been very reliable. In case you do want to go aftermarket, I run Speedhut gauges and the fuel gauge can be calibrated to the individual sender, not just the typical mopar range. I get accurate readings and the needle doesn't bounce around hardly at all.
I currently have Autometer gauges. The autometer gauge is calibrated to the Mopar sending unit. I'll look into the the Speedhut gauges, Thanks.
 

73Dodge

Member
Joined
Dec 8, 2020
Messages
15
Reaction score
7
Location
USA
My pleasure. Hey a silly thought but just throwing it out there, to verify the sender is clocked correctly in the tank. If it's in at an angle it can read as your describing. Typically there's tabs on the tank that line it up correctly as you insert it.
 

money pit

Well-Known Member
Joined
Nov 17, 2017
Messages
447
Reaction score
44
My pleasure. Hey a silly thought but just throwing it out there, to verify the sender is clocked correctly in the tank. If it's in at an angle it can read as your describing. Typically there's tabs on the tank that line it up correctly as you insert it.
I had thought about that but the sending unit will only go in one way because of the tabs. Thanks
 

Charlie71rt

Active Member
Joined
Dec 7, 2016
Messages
38
Reaction score
4
Had mine rebuilt by TriStarr inexpensive, quick turnaround and it works perfect

1DB2ACB1-BB2A-424E-8719-6E683E1708E6.jpeg
 

money pit

Well-Known Member
Joined
Nov 17, 2017
Messages
447
Reaction score
44

ctaarman

Well-Known Member
Joined
Nov 8, 2016
Messages
95
Reaction score
20
If it is jumping around, don't ignore the possibility that it is either the wire from the fuel gage to the sending unit that has deteriorated, or the 12V feed to the fuel gauge that has the same issue. Check those before you buy any more sending units.
 

money pit

Well-Known Member
Joined
Nov 17, 2017
Messages
447
Reaction score
44
If it is jumping around, don't ignore the possibility that it is either the wire from the fuel gage to the sending unit that has deteriorated, or the 12V feed to the fuel gauge that has the same issue. Check those before you buy any more sending units.
I ran a new wire from the sending unit to an aftermarket gauge (Autometer) that operates on 12v. Thanks
 

themechanic

Well-Known Member
Joined
Aug 16, 2019
Messages
152
Reaction score
46
Location
Moore, OK
Lots of folks are buying add-on controllers to calibrate their sending units. Much cheaper option than NOS.

Speedway sells one and others. FBBO has some threads on the subject.
 
Top