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TR6 Fuel gauge diagnostics conformation

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Gliderman8

Gliderman8

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Took my TR6 out on Sunday for the first drive of the season. Fuel gauge showed about a 1/2 tank. When I looked at the gauge a few mins later, it showed 1/8 tank. To be sure I didn't run out of fuel, I added 4 gallons to the tank. The fuel gauge did not move off the 1/8 mark.
OK, here's what I did to diagnose the problem:
  • Grounded the fuel sender and the needle on the fuel gauge moved to Full. This tells me that the gauge is working
  • Measured the voltage at the sender and the temperature sensor. Both showed 10v. This tells me the solid state voltage regulator is also working.
The above diagnostics only point to a bad sender in my mind. My sender has a brass float so I don't think it is full of fuel.
I'm getting ready to order a new sending unit but before I place my order, is there something I missed? Do you agree with the diagnosis that it could only be the sender?
 
Certainly no expert here! but there's also the possibility of a loose or frayed wire inside, or at the tank, or even a voltage fluctuation, causing the symptom. Also,, how old is the sender unit?
 
NutmegCT said:
Certainly no expert here! but there's also the possibility of a loose or frayed wire inside, or at the tank, or even a voltage fluctuation, causing the symptom. Also,, how old is the sender unit?
Click to expand...
No voltage fluctuations; I monitored voltage with my meter. No loose connections. Sender is 53 years old... wonder if it's under warranty :D
I'll probably just replace it
 
Brass floats can fail. Or the pivot mechanism may be gummed up, Can you pull the sending unit to check?
 
Mickey Richaud said:
Brass floats can fail. Or the pivot mechanism may be gummed up, Can you pull the sending unit to check?
Click to expand...
Thanks Mickey. Unfortunately the tank is pretty full so it’s going to be hard to move the tank out enough to remove the sender. I’m going to borrow a small hand pump to remove some of the “go-juice” and see what’s going on.
I installed the brass float years ago since the plastic one leaked.
I’ll know more after I pull it, but once everything is apart I hate to then have to wait for a replacement or put the old sender back in and have to remove it again for a replacement. Can’t win.
 
To be honest ... a high school girlfriend (yes we keep in touch) heard of my sender problems in my '53 MGTD. So she sent me a quick fix -

a yard stick

Hold it straight down to the bottom of the tank, with 0 at the bottom and 36 at the top. Each inch that's wet up from the tank bottom, is one "gallon". Works for me.

TM
 
NutmegCT said:
To be honest ... a high school girlfriend (yes we keep in touch) heard of my sender problems in my '53 MGTD. So she sent me a quick fix -

a yard stick

Hold it straight down to the bottom of the tank, with 0 at the bottom and 36 at the top. Each inch that's wet up from the tank bottom, is one "gallon". Works for me.

TM
Click to expand...
If Fred Flintstone had a fuel tank he might use that method. :ROFLMAO:
I’m going to get my gauge working.
 
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