Fuel Gauge problems
 

I'm swaping in a 1kzt and the full wiring loom. The fuel sender and fuel gauge were working perfectly fine before I removed them. I've put in the wiring loom into my truck and went to test the sender/gauge. When I plug it in, the gauge goes straight up to full. When the fuel sender is unplugged the gauge stays. I've tried grounding the positive wire and nothing happens. I also tried pluging into both the fuel senders(which both worked perfectly fine) and the reaction is the same.
Can anyone suggest any test I can do to figure out what is wrong? or any other possibilities of what is wrong?

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What model and year is the truck that you put the 1Kzt in.

Unless you installed dual tanks, where did you find the second fuel sender?

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The truck it's going into is a 93 Hilux. The 1kzt/wiring loom is from a 95 4Runner.
I've tried connecting the fuel sender from my 93 and also the fuel sender from the 4runner, but the problem is the same with either so I'm fairly sure that the fuel sender is not the problem....also they were both working perfectly before the swap...and so was the gauge in the cluster.

anybody?!!

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I recently rebuilt my fuel sender, took it all apart made a new top for it, tack welded the wiper assembly back on it and tested it. The resistance values were perfect for full, half full and empty as per the FSM. I put it back in my 86 pickup and nothing. I tested the gauge as per the FSM (3/4 watt bulb in the circuit to ground and the gauge went to 1/2 full like it was supposed to. So I ordered a new sending unit from Toyota, it wasn't exactly like mine, the mounting hole locations had to be re-drilled and the float wiper arm was shorter. (The new unit was for a short box pickup or 4Runner with a 17 gallon tank, my truck is a long wheelbase with a 19 gallon tank.) I put the new unit in filled my truck up and nothing, so I said to heck with it (my low fuel light worked) and then I drove 15 minutes into the city. Somewhere between running my errands and driving back home my fuel guage started working and it's been fine ever since. The point of this essay is there may be nothing wrong with your fuel guage or sender (mine tested according to the FSM specs) it may just need some bouncing around to get it jump started.

If it was fine before you started the swap, try it and see what happens.
Good Luck

Thanks. I will keep that in mind if all else fails!