63 Spyder, joining the failed gas gauge group..

[Grandpacorvair]

I think I am going to be VERY happy when the driving season is over.. (which should be this week, for me)

I'm getting a bit frustrated with the odd issues my car has come up with this Fall... sigh.

Anyways getting the car ready for storage. Car had about 1/4 of a tank of gas. Went to the station, added some stable and filled the tank. Started it up and the gas gas now reads less than 1/4 tank! Ok... problem... Drive it home hoping it would somehow fix itself. (it didn't) so I decided to make a few checks. First was to verify that connections uder the dash were ok. Then I disconnected the sender wire at the tank and the gas went up to beyond full, connecting it back up sent the gauge back to less than 1/4. Measured the resistance between the sending unit and the tank and got around 6 ohms. IF I understand the gauges operation, on a 63 that should have read upwards of 30 ohms with a full tank of gas. Not good. I'm thinking either the sending unit is stuck OR the float has come off of the arm.

I'm just checking to see if I have this diagnosed right and asking what's involved in pulling the sending unit..?

Figures it fails when I have just filled the tank! argh...

[miniman82]

Probably time for a new sending unit. The actual sending unit is just a wire wound potentiometer, and that wire is very very thin. Over time it can wear out, or even break. When that happens, you will get erractic readings or no reading at all. It's a simple thing to replace, Clark's has all the parts you will need.

[terribleted]

Very likely the problem is at the sending unit end. The gauges are generally pretty reliable, the sending units not so much. A stuck float arm, a leaky float could indeed be the problem. Pretty simple to pull the sender out and check it out as long as the gas tank is not full:) The 61 GM shop manual suggests to temp wire a new sender to the gauge to check gauge operation, and then to proceed to removing the sending unit if all looks good at the dash end. First before anything else check tighten and clean the wiring connections at the sender and perhaps at the back of the gauge as well. Pay particular attention to the ground wire from the sender to the body of the car.

[Grandpacorvair]

Anyone know how empty the tank needs to be?

[terribleted]

Anyone know how empty the tank needs to be?

All the way empty. You remove the body side of the hose from the sender to the body fuel lineand direct it into a suitable catch container and wait till it stops dripping. then you remove the sender.

The GM shop manual outlines the procedure in detail. If you do not have the shop manuals you should get them, I do repair professionally and I would not do repairs without one close by at least.