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Topic: Gas Gauge Above Full (Read 2753 times) previous topic - next topic

Gas Gauge Above Full

Alright guys, tonight the 5.0 transplant finally went down the street, and after a few minor adjustments it shifted fine through the gears.

Now on the way back the full gague will all of a sudden went all the way to full.  Since last week when the car took its first breath in the new car the gas gague has been teetering half way. Now all of a sudden it went to full. Now I am thinking its a ground, it worked fine earlier and I'm hoping its not the sending unit in the tank. Any suggestions?

Gas Gauge Above Full

Reply #1 –
Anyone? I've checked the ground on the back side of the dash(the drivers side) and it seems fine. The gauge automatically goes to full. I'm thinking this is a ground problem somewhere...As usually they go to "E" is the sending unit is bad, right?

By the way when I turn the key off it goes to "E" like normal, but when the key is on, it immediately speeds its way to past full. Its not instant but definately faster than normal.

Anyone had a similar problem?

Gas Gauge Above Full

Reply #2 –
Sometimes the voltage regulator on the back of the cluster can cause the guages to top out their readings.  Though if it's an buttstuffog cluster all the gauges will read high.  Which gauge cluster do you have? 

My buttstuffog will act up occassionally.  If I tap on the cluster it will begin to work correctly. 

Not exactly a technical solution, but if you tap on it and the gauge begins to read correctly, at least it will isolate it the cluster.  If it has no effect, you will still have to test the wiring to the gauge...

Gas Gauge Above Full

Reply #3 –
Well i just got the temperature working, It reads in the middle of the gauge, so I'm assuming that is normal for a stock 5.0. Its the base cluster.

I've tried tapping on the dash to no avail. When the motor first ran the gas gauge was about halfway up, about where I think it should be.

I read through the CoolCats and it mentioned tapping on the gas gauge too in order to try and isolate that. Neither have caused the problem to change. What grounds should I be checking? Anything else?

Gas Gauge Above Full

Reply #4 –
Alright, well ive checked everything I can think of. It appears its either the gauge or the fuel sending unit. Where can I get a sending unit, everywhere I call seems to have a fuel pump and sender in one. My fuel pump is only about 6 months old, I just want a sending unit.

Gas Gauge Above Full

Reply #5 –
Check the sender to see how many ohms it's sending out. If it reads off the scale, it might be grounding it's self out.
It should only be about 8-12 ohms at full
and between 60-86 ohms empty.
These are buttstuffog readings
I've been doing some experiments with one in the last week
[SIGPIC][/SIGPIC]
***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
[/COLOR]
5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
Pretty much every panel on my 87 is new, rebuilt, or re constructed. :D
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Gas Gauge Above Full

Reply #6 –
Are you doing this at the pins in the dash? where you getting the readings from?

Gas Gauge Above Full

Reply #7 –
You should get the reading off the 2 wires that come from the sender.
Not sure what color they are at the dash. I'd have to look them up.
[SIGPIC][/SIGPIC]
***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
[/COLOR]
5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
Pretty much every panel on my 87 is new, rebuilt, or re constructed. :D
Join us on Facebook
http://www.facebook.com/home.php?sk=group_137541156293768&ap=1

Gas Gauge Above Full

Reply #8 –
Also does anyone know which fuel sending unit is discontinued. I read an earlier post and someone had a base cluster and couldn't find a sending unit. Can anyone confirm that the base sneding units have been discontinued or was it the full digital sending units?

Is there even a difference between the two of them? If so, what is it?

Gas Gauge Above Full

Reply #9 –
looks like a yellow/white and a black ground wire
[SIGPIC][/SIGPIC]
***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
[/COLOR]
5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
Pretty much every panel on my 87 is new, rebuilt, or re constructed. :D
Join us on Facebook
http://www.facebook.com/home.php?sk=group_137541156293768&ap=1

Gas Gauge Above Full

Reply #10 –
The digital sends the ohms reading in reverse

full= empty
empty=full

From what I understand it was the digi sender that is a bear to find
also, most places list the pump as a sending unit.
[SIGPIC][/SIGPIC]
***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
[/COLOR]
5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
Pretty much every panel on my 87 is new, rebuilt, or re constructed. :D
Join us on Facebook
http://www.facebook.com/home.php?sk=group_137541156293768&ap=1

Gas Gauge Above Full

Reply #11 –
I may have also found a way to turn 1 into the other. :D
[SIGPIC][/SIGPIC]
***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
[/COLOR]
5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
Pretty much every panel on my 87 is new, rebuilt, or re constructed. :D
Join us on Facebook
http://www.facebook.com/home.php?sk=group_137541156293768&ap=1

Gas Gauge Above Full

Reply #12 –
can you explain? I have one from a digital cluster than seemed to work fine... Im assuming now they are different. Please help me... :)

Gas Gauge Above Full

Reply #13 –
Wait a minute.
If the sender came from a base digital cluster,with a regular gauge, then it will work the same.
If it came from a full digital cluster including digital gas gauge. Then it reads opposite.
I wasn't sure which one we were talking about.
[SIGPIC][/SIGPIC]
***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
[/COLOR]
5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
Pretty much every panel on my 87 is new, rebuilt, or re constructed. :D
Join us on Facebook
http://www.facebook.com/home.php?sk=group_137541156293768&ap=1

Gas Gauge Above Full

Reply #14 –
he has a parts car with the full digi with a working good sensor...

The car which isn't his parts the one with the problem is a Base Cluster...  which is a bad sensor...  Also a different fuel sender then the full digital...

They make the full digital still but not the basic cluster, and the buttstuffog and basic cluster share the same unit...


He wants to know how can he use the full digital sensor with the base cluster...  If u have a way of course...
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