Gas Gauge/Sending unit issues
Thread Starter
Heel & Toe
Joined: Nov 2015
Posts: 16
Likes: 0
From: Nampa Idaho
Gas Gauge/Sending unit issues
Hello,
I changed out the Gas Gauge and installed a new sending unit, my issue, is when I drive the gas gauge changes while turning, it can go all the way to empty or up towards 3/4. I'm guessing this has something to do with a Ground? Any suggestions, I did the testing as explained on Wilcox. com and the fuel gauge functions as expected with taking off the wires. Past full with the sensor wire off, removing the ground takes it all the way to empty. As I stated new gauge and sending unit, same problem still exist, with the exception it moves around more then with the old stuff.
Thanks in advance for any suggestions on resolving this.
1973 C3, 350 ci, Automatic, Coupe
I changed out the Gas Gauge and installed a new sending unit, my issue, is when I drive the gas gauge changes while turning, it can go all the way to empty or up towards 3/4. I'm guessing this has something to do with a Ground? Any suggestions, I did the testing as explained on Wilcox. com and the fuel gauge functions as expected with taking off the wires. Past full with the sensor wire off, removing the ground takes it all the way to empty. As I stated new gauge and sending unit, same problem still exist, with the exception it moves around more then with the old stuff.
Thanks in advance for any suggestions on resolving this.
1973 C3, 350 ci, Automatic, Coupe
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Sounds like the gas moving with centrifugal force to the side is making the gauge move. Maybe the floats axis is not pointing front to back but is side to side. When going up hill or down it should change level a small amount. Is it installed exactly as the original. Maybe check your AIM if you have one.
Racer
Joined: May 2011
Posts: 373
Likes: 6
From: Dover Delaware
Having the same issues w/my 78
Hello,
I changed out the Gas Gauge and installed a new sending unit, my issue, is when I drive the gas gauge changes while turning, it can go all the way to empty or up towards 3/4. I'm guessing this has something to do with a Ground? Any suggestions, I did the testing as explained on Wilcox. com and the fuel gauge functions as expected with taking off the wires. Past full with the sensor wire off, removing the ground takes it all the way to empty. As I stated new gauge and sending unit, same problem still exist, with the exception it moves around more then with the old stuff.
Thanks in advance for any suggestions on resolving this.
1973 C3, 350 ci, Automatic, Coupe
I changed out the Gas Gauge and installed a new sending unit, my issue, is when I drive the gas gauge changes while turning, it can go all the way to empty or up towards 3/4. I'm guessing this has something to do with a Ground? Any suggestions, I did the testing as explained on Wilcox. com and the fuel gauge functions as expected with taking off the wires. Past full with the sensor wire off, removing the ground takes it all the way to empty. As I stated new gauge and sending unit, same problem still exist, with the exception it moves around more then with the old stuff.
Thanks in advance for any suggestions on resolving this.
1973 C3, 350 ci, Automatic, Coupe
Having the same issues with my 78.....Can I do the sensor/gnd wire off test and try that on my 78??? Before I try it can you tell me which wire is which I just wanna be sure because it is right close to the tank neck????
Cordially,
mk's78 Mike
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
Sounds like the gas moving with centrifugal force to the side is making the gauge move. Maybe the floats axis is not pointing front to back but is side to side. When going up hill or down it should change level a small amount. Is it installed exactly as the original. Maybe check your AIM if you have one.
It is pretty hard to install one of these wrong as the vent and fuel hose lines are pretty specific. It is conceivable that you could be one bolt hole off but I'd bet against it.
If the reading is solid when full, empty and at a standstill, I'd say the sloshing reading is pretty ops normal.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Fuel gauge sway is usually do to the movement in the gauge has leaked out the oil. The fuel gauge has dampening oil inside that is supposed to dampen (or delay) any sway when you turn a corner. Aside from this oil, a fuel gauge and a oil pressure gauge are exactly the same. You'll notice that a oil pressure gauge is very responsive and has a lighter oil inside. As the gauges age, the oil can dry up and when this happens you end up with a very (over) responsive fuel gauge.
Five or six years ago Roger and I tried to figure a fix out for this and there is one but it involves putting a capacitor on the fuel gauge to delay the reading. You can probably search archives and find a thread or two where we started to cross this bridge. My translation to this was time vs. money.... If you are taking the time to remove the gauge to do this why not just replace the gauge. I created a fix.. then nixed it instantly.
Willcox
Wow.. I guess it was longer ago than I realized, my picture below is dated 2006 lol
Five or six years ago Roger and I tried to figure a fix out for this and there is one but it involves putting a capacitor on the fuel gauge to delay the reading. You can probably search archives and find a thread or two where we started to cross this bridge. My translation to this was time vs. money.... If you are taking the time to remove the gauge to do this why not just replace the gauge. I created a fix.. then nixed it instantly.
Willcox
Wow.. I guess it was longer ago than I realized, my picture below is dated 2006 lol
Last edited by Willcox Corvette; Jul 3, 2016 at 06:18 PM.
Thread Starter
Heel & Toe
Joined: Nov 2015
Posts: 16
Likes: 0
From: Nampa Idaho
Best of luck to you...its really a simple procedure.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Without changing anything, turn ignition key to ON (engine off) and have someone watch the gauge will you get under the rear. First, wiggle the ground wire around to see if the gauge reading will change. If not, then wiggle the sending unit wire around to check for gauge change.
I suspect that one or the other wire is broken or frayed inside the insulation. As you drive, the wire gets moved and reads...or not...as the wire makes/breaks connection.
I suspect that one or the other wire is broken or frayed inside the insulation. As you drive, the wire gets moved and reads...or not...as the wire makes/breaks connection.
Thread Starter
Heel & Toe
Joined: Nov 2015
Posts: 16
Likes: 0
From: Nampa Idaho
Without changing anything, turn ignition key to ON (engine off) and have someone watch the gauge will you get under the rear. First, wiggle the ground wire around to see if the gauge reading will change. If not, then wiggle the sending unit wire around to check for gauge change.
I suspect that one or the other wire is broken or frayed inside the insulation. As you drive, the wire gets moved and reads...or not...as the wire makes/breaks connection.
I suspect that one or the other wire is broken or frayed inside the insulation. As you drive, the wire gets moved and reads...or not...as the wire makes/breaks connection.
Thanks for your response to my post, really appreciate everyone's thoughts and ideas.
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Thread Starter
Heel & Toe
Joined: Nov 2015
Posts: 16
Likes: 0
From: Nampa Idaho
Thanks for sharing your thoughts, I have done that by myself, not able to prove anything as one would expect. I did find the ground wire was very lose on the connection, so I have tried to tighten that up, seemed to help some. Will try your complete idea tomorrow when a friend stops by and see if it is only a lose connection.
Thanks for your response to my post, really appreciate everyone's thoughts and ideas.
Thanks for your response to my post, really appreciate everyone's thoughts and ideas.
I plan on taking the dash apart again, I will check all the connections, as I plan on changing out the speedometer and cables this fall. Hopefully then I will be able to isolate this issue. Also, I haven't driven the car much since I changed the sending unit, as I have the AC apart. AC should be together tomorrow, hopefully then I will drive the car, fill the tank and see how the gauge performs. Again, Thanks everyone for your help and suggestions.