Thoughts on my gas gauge situation?

[davepl]

I had a tech install an in-tank pump and level sender from Tanks, Inc.

The first time we flipped the tank upside down (to try to cause the sender to read full) it only read 33 ohms, so I left him to sort it out.

When I picked the tank up he said he tested it and it ran exactly 0.5 to 90.5 ohms.

I installed the tank, added about 4 gallons, and it read just over empty, so far so good.

I drove it to the gas station and added 5 more, but the needle didn't move.

Now it's got fuel in it and I really don't want to mess with it. I just can't picture what might be going on that it worked on the bench and not in the car.

[dmjlambert]

I suppose the float could be filling with gas.

['68OrangeSunshine]

If you do it yourself, you can afford to try and err, until you get it right.
If you pay a pro, he was paid to get it right the first time. It should be on him.
Take it back and have the pro correct the situation.
If you mess with it, he could say ''well, you did it.''

[toolboxchev]

Float is stuck. Is this the original style for our trucks? My thoughts are when it was turned upside down one part of the mechanism shifted to one side.

[davepl]

Originally Posted by '68OrangeSunshine

If you do it yourself, you can afford to try and err, until you get it right.
If you pay a pro, he was paid to get it right the first time. It should be on him.
Take it back and have the pro correct the situation.
If you mess with it, he could say ''well, you did it.''

Oh I agree, just the sucky part is now it has gas in it and is installed in the car, whereas it was bench work on a new dry tank when I took it in.

I did everything else myself on this EFI install and it all works, so annoying that the one part I had done professionally went sideways :-( But my mom was a burn ward nurse and I'm now so paranoid about gasoline that I don't like working on tanks.

This is not actually on my truck (but not a truck-specific issue other than tank shape I suppose) it's on my '69 Impala, using a Tanks Inc sender TAN-GML which is their 90 ohm unit.

I was thinking of filling the tank to see if that might "pop" the float loose from whatever it's hung up on.

If it worked and shows 90 ohms when the tank was upside down I guess it must be hung up or stuck somehow, as you guys say.

[randy500]

Put a ohm meter on the tank to frame and see if it’s properly grounded.

It seems to me that he told you what you wanted to hear...90 ohms sir!

['68OrangeSunshine]

So you may have let the pro off the hook. You might still ask him what he thinks.
I took my drivers ed in '63 Impalas, donated to the school by the local Chevy dealer. I would guess they also have a 20 gallon tank. Fill the tank and see if that frees your float.
If not, and you have 4 jerry cans and a siphon pump you could empty your tank, drop it from the frame and pull the sender to see what's up. Use a brass bar and strike it off with a neon orange dead-blow hammer for no-spark security.
Don't smoke while extracting the sending unit.
If the float is saturated replace it. Look inside to see if the action isn't catching on some internal baffle. Truck tanks don't have them, but I'm unfamilar with sedans.

[dmjlambert]

If you have another vehicle with a near full tank and it does not have one of those siphon guards in the filler neck, you could siphon the fuel from it into the truck. In the event you need to empty the truck tank to investigate, siphon the fuel back into your other vehicle. That way you won't have to cart gas from the gas station in small containers, and you will have a place to store fuel if you need to remove the truck's tank. You may need to use a small container to cart the fuel between the vehicles.