Friday, July 24, 2020

Fuel Gauge, The End Of A Saga?

Despite seeming to work after we tracked down a faulty connection on the fuel sending unit, the fuel gauge is still not reading accurately.  Troy said he would help me replace the fuel sending unit, figuring that was the only thing we had not tried in an attempt to get the digital fuel gauge to read right. So on Saturday, June 20th we set to it.

Can you take me high enough?
To fly me over (fly me over) yesterday
Can you take me high enough?
It's never over, yesterday's just a memory

Okay, so blame my 80s playlist, but I had this song running through my head the morning we lifted KARR.


The first thing we did was remove the cross brace that supports the fuel tank.


Next we disconnected the ground wire that I added in an attempt to make sure the tank was properly grounded, along with all the fuel lines.


We removed the fuel tank straps so we could lower the tank.


There was more gas in the tank than I realized and it came pouring out the back as we lowered the tank.  If only I had a fuel gauge that worked...  We siphoned all the gas out of the tank and removed the tank.



Next we removed the fuel sending unit lock ring.


With the fuel sending unit out, we could see that the contact was not making a solid connection, most likely causing the erratic readings.




Although the picture did not capture it very well, you can literally feel the new sending unit making contact as you move the float up and down.


What you are actually feeling is the contact passing over each of the ribbed contacts on the printed circuit board portion of the fuel sending unit.


We had to splice the connector for the fuel pump onto the connector for the new sending unit.


Just for curiosity's sake, we decided to test the ohm reading of the old fuel sending unit as the float traveled from its lowest position to its highest position.  This should read 0 to 90 ohms.  The readings below are taken in order as the float arm was put through its full travel.










As you can see, the readings are all over the place, and well over 90 ohms, proving the fuel sending unit is faulty.


New fuel sending unit installed.


I secured the harness with zip ties and reused the rubber grommet from the old sending unit.


Because we struggled more than we should have to get the fuel tank out with KARR on Troy's center post lift, we needed to raise KARR up higher on the lift.  We lowered him down and added blocks to the lift's risers to give us more clearance for the fuel tank.


With the fuel tank back in place and secured we hooked up the fuel lines.


Remember the coolant line brackets that needed to be replaced?  I ordered a set from The Fiero Store.  The first bracket literally fell apart in my hands when I removed the bolts.


Here I am holding the new bracket in place.



You can see on what is left of this bracket that there was an insulating rubber pad that has long since deteriorated.  Troy and I had the idea of cutting apart a rubber hose to make new pads since the brackets did not come with any.


New bracket and rubber pad installed.


The rubber seemed to work great and we followed suit with the remaining three brackets.











While car was in the air I took pictures of some things I still want to repair or replace.  The first is the license plate light lenses.  One of the screw's heads had twisted off and was no longer securing the lens.  They are also badly oxidized.


The radiator/cross member braces also need to be replaced.



The subframe connector is also in pretty bad shape and needs to be replaced.


With KARR lowered back down, we siphoned the fuel back into the tank.


Two other items I would like to see if I can find replacements for.  The first is this plug on the rear quarter section of the car.  It faces the deck lid.


I also noticed the washer is missing from the rear deck vent on the driver's side.


Only time will tell if we can get the fuel gauge adjusted to read correctly now.

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