Fuel Gauge accuracy

[stushug]

My original sender is long gone, so there's no option of rebuilding it and re-installing it. The one that's in there now is a new chinese crapper, but that's all that I could find and I figured it's better than no gauge at all. The problem is that once installed it sucks for accuracy. I had tested it before installing it, and it did (barely) reach full when I moved the float arm to that position. When I moved the float to the other extreme, the gauge read empty. I did measure the ohms, but I don't remember what the exact numbers were but the must have been close to original specs. I filled the tank yesterday, and while still sitting at the gas pump the needle only went to a touch over 3/4. I'm guessing that once the gauge is in the tank, the float range of motion is not as full as when it was outside of the tank and the float level never moves the arm far enough to register full. What is confusing, though is as I drove around, the need occasionally did go to the full mark, but it kept going back to about 3/4 and mostly stayed there. I just checked it again with the car sitting still in my garage and the gauge only went to 3/4. I remember someone in another thread mentioning meter match. Would that box correct my problem? Thanks guys!

 

[pnora]

Meter Match is your answer.

 

[wagonman]

For one thing yes Vachina crapola next they are not linear meaning move a certain amount for every gallon used. I have one from right Stuff and It seems to be the best of the bunch. Sourced over seas I am sure. At E it takes 9-10 gallons and goes a small bit above full. hella Reserve. I have had it out bending the float arm small amounts at a time to get close to accurate. One more tweak and it should be spot on. But I would rather have a 2 gal reserve than be dead E at E. Thats why I am the only driver plus other reasons, Read its not my car so I can beat the snot out of it reasons. My Duster with new tank and sender is the same But I run the same amount of fuel for taking it to the track, right on 1/2 tank. Gets Low Put it to 1/2 and get about 40 miles before adding again. Thats hard max miles.

 

[Timmayy]

I just installed one in my wife's 67 Fury wagon from Van's Auto. The previous owner had a cheap aftermarket one and I could not get it to work correctly. The people over on FCBO said they have better quality units. I just installed it yesterday and so far it seems to work. I don't know exactly how accurate but it does work.

 

[stushug]

After acting on a hunch, I checked the tank. I was able to add almost 5 gallons today, that means the auto-shutoff at gas station fuel pump shut off way before the tank was full. I did add some afterward, but I guess it wasn't enough. The tank probably was only 3/4 full, that's why my gauge only went to that mark. I guess the only reason it went to full a few times while I was driving was because the float was moving a bit when the fuel in the tank was sloshing around. I'll keep an eye on things, and if I notice the gauge is constantly incorrect, I will probably add the meter match.

 

[blue69runner]

Do you have the original tank in the car or an aftermarket. My aftermarket tank and sending unit had a problem with reading right. Took the unit out of tank and had to bend it more to the front of the tank and closer to the flat spot there. Problem solved. Now it reads close enough. When pump kicks off gauge reads full. Have checked it at or near empty and the right amount of gallons are needed to fill the tank. Wish you luck with it. Some of these just seem to drive you nuts.

 

[stushug]

Aftermarket tank. Before I installed this newest sending unit, I dropped the tank and installed the sender while I could still see it through the filler hole. I made sure nothing was interfering with its range of motion. I'd had that problem with another sender, so I knew to look for that. Then I hooked the sender to the gauge while it was out of the tank and tweaked the float arm to get it to read the proper readings at full, 1/2 and empty. Only then did I do a final installation of everything.

 

[gary h]

check for a leaky float.

 

[stushug]

Well it seems this little drama isn't over yet. Last evening I took the car out, and knowing that the tank for sure is full, I looked at the gauge and the needle was significantly past the full mark. That tells me the resistance coming from this sender when the tank is full is off enough to cause the gauge to read too high. I ordered the meter match when I got home last night, and when I get it I'll calibrate to get the correct readings. I'll also get exact ohm readings as I go for reference. I don't have the FSM in front of me but I think it's supposed to be around 70 ohms empty and 10 ohms full. Whatever it's supposed to be, I'll set it straight with the meter match.

 

[Mackman]

Good luck.