fixing erratic fuel level reading

My fuel gauge kept jumping around, but mostly reading full when full then after awhile reading empty with the gas pump on the dash illuminated. I forgot to take a resistance reading but I believe that you have voltage to the sending unit and when full it has high resistance and low, a lower resistance. What the problem is that the sweeper on the sending unit starts to not make a connection in the middle of the variable resistor and it goes to empty.
I could not get any info on how to remove the sending unit on a 360 Modena, which is behind the driver. The spider is different set up.
First get a stick to hold the engine bay open. Take the strut off the driver’s side. You do not have to unbolt anything. There are little clips at each end. (clip pic)#1
You then have to take out all the little screws out of the side cover panel. They are a torx head. You have to be real careful not to drop any.
Next take off the insulation off above the fuel pump. It has 2 round black clips that you get off by twisting and turning at the same time.
You are ready to remove the items that are connected to the fuel pump. The hoses have plastic connectors that get off by pushing in on the connector with one hand and pushing in on the little tabs with the other, then pull off. You always have to be gentle with plastic parts, because they like to break! I was pleased that so far all of the Ferrari plastic is better quality than other cars I have worked on. You have to take off the fuel pump hose, you can follow it to the injector rail to ID it. Notice it is pointing to an arrow, as you will need to line it up again when installing the pump back in. You need to take off the fuel bypass fitting off the aluminum tube on the firewall. Then turn the plastic piece on the other end of the hose CC to remove it.(pic of top of tank#3 ) Next take off the electrical plug. Next take the plastic ring off CC.
Now you are going to do the hardest thing. If you have clumsy or real big hands this will be difficult. You have to have REAL patience also. Blow off the area with air to remove any dirt. The 8mm screws are hard to get at and get out without dropping them. You need ¼ inch drive sockets to do this. Also have a fan ready to blow the gas fumes away from where you are working as much as possible.
After pulling the fuel pump up and out, the sending unit arm was hanging up. I took it loose from the sending unit first, by pulling it out of the plastic keeper. ( arm pic #2)
My sender must have been replaced. The return to fuel tank hose clip was damaged and I have an oval float. When you have a rest or the next day if you have breathed too many fumes (I am not kidding) you need to take the sending unit apart. The arms need to be bent just a little to make better contact. (sweep arms pic #4) Put the float and arm back on the sending unit if you took it off. Move it back and forth. It probably will not have any noise or feeling. Take the sweep contacts off the variable resistor. (resistor pic). You have to be very careful not to break the plastic when lifting it off the brass shaft. After bending the arm, put it back on and you will hear and feel something like a zipper unzipping.
Next, installation. I put the float and swing arm back on the sending unit, since I know where it is going, towards the rear of the car. Feed the float and arm carefully towards the back of the car. Next have fun putting all the little screws back in the top housing. Next put the rubber gasket on the housing FIRST then push down on the fuel pump to depress the springs. Mine stayed put after I shoved it down without the big plastic nut.
The rest, just hook up plug and hoses in reverse. Blow off the area with air, a shop vac works well. I left the side panel off, took the stick out and closed the engine bay cover and went for a short drive, making hard left and right turns to make sure of no leaks. You should smell NO gas.
Presto, my gas gauge works now!
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