How do I get to a GTd40 fuel sending units

I have one fuel guage that bounce from full to half once and a while the other guage is empty and never moves. I ran out of fuel once and the only reason people helped is because it was a GT 40 .
 

Ian Anderson

Lifetime Supporter
Fill both tanks
Drive on the tank that reads empty
When you hear your fuel pump suck air (under braking normally)
Click to the other tank
Drive it another 50 75 miles and refill both

Been doing it for 7 years now and it works out fine!
 
Paul, you don't need to do either initially ! the simplest and first check is to remove the two small covers on the rear sill top panels in the engine bay ( 4 screws each ) and remove the wire from the central terminal on the sender unit located on the top of the fuel tank under this panel. With the ignition on put that wire directly to a chassis earth ( any metal part of the chassis that is conductive ) and the gauges should read full ( maximum ) If this is correct then the problem is the sender units in tanks, and these should be replaced . This is the most likely and common fault on this type of fault. Frank
 
I have the capacitance sender, and it works flawlessly. The setup of the sender is a piece of cake. They are pretty sensitive on changing with the level as noticed when a slosh occurs(I have a trap door arrangement as well as partitions in the tanks). What I particularly like is the ability to add a warning light for a low level alarm. The light catches your eye rather quickly. Once I see the level fluctuating I know that if I can cruise on level ground for 30 seconds I can get the true level of the fuel(primary tank only). I have a trap door arrangement around my pickup tube, and a cross over line(which I feel is too small for true filling of the primary tank as I drive). Last time out I noticed I was getting pretty low and decided I would fill up before leaving to return home. When I cranked up to leave, the primary tank was full!! So this winter I will make an effort to increase the size of the cross over. As I remember it is a 3/8" line.
My gauges are Stewart Warner Maximum. When you order the sender you specify the resistance value of your gauge. They have them all covered.

Bill
 
I bought them direct from the states from a company called skysports - designed for light aircraft I believe. Here's a thread I found with a quick search, pics are similar to mine...
Dynon Avionics
Forum - Fuel Senders & Calibration

My senders have straight pickup tubes and 3 posts on the tops for the wiring.
You adjust the two grub screws for full/empty on the gauge and I used the standard smiths gauges from Caerbont automotive uk.
The gauges do go up and down with a kind of delayed reaction to heavy braking/Accel.
I'm pretty pleased with them as the foam in my tanks surrounds them completely.
 

Mark Charlton

GT40s Supporter
Lifetime Supporter
Paul,

When I had this experience on my GTD, the first thing I did was check I the resistances at the senders (which checked out as ok). In MY case, it turned out the be some dodgy connections at the gauges themselves, along with one needle that was dragging just a bit on the gauge faces.

The advice posted here is good, but if your senders check out ok then clean all the contacts and connections before spending any money. It worked for me but as they say, your mileage may vary.

Mark
 
Back
Top