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Hi All,
On my Spica injected 74.
I filled the tank the other day and the gauge stayed at Zero... or near to it.
I was unsure so I refilled it next time... it took a gallon, so its FULL!
I checked the connections... all ok..
Sometimes it reads up to half...
But not full!
Ideas?
Also my Low Fuel Pressure light is flickering on and off... I think these two are unconnected but just thought I would mention as it happened at the same time.
Mostly when I give full acceleration... but not always.
Before you ask, I am going to change the filters...
Ideas on who the best supplier is and what to order?
 

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I had a very similar problem on my 72 Spider (Weber carbs) a couple of years back. The empty light was OK, but the needle varied from jumping crazily to doing nothing at all. I tried a new sender unit, new fuses, and even ran a new wire between the two- all with no effect. Finally, I realised that one of the terminals on the back on the gauge had turned slightly and was just touching the mounting bar, earthing it, and creating a false signal.
 

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They are two unrelated problems. First of all, check your fuses.

For the fuel gauge, there are two wires on spade terminals on the fuel tank sending unit. One is for the fuel gauge needle, the other for the low fuel warning light. Disconnect the wires, turn the ignition on, then momentarily ground the wires to the body one at a time. You should see the fuel low pressure warning light come one, and then the fuel gauge go to full scale deflection (full indication). That tests the dash gauge. If you don't get those indications, then it's possible that either the wiring or sending unit is bad.

On the fuel low pressure warning light, it could be as simple as a clogging rear fuel filter. Download the fuel systems diagnosis guide at:
www.wesingram.com/hp.htm

Rear fuel filters are available locally. The front filter will have to be ordered. The problem could also a failing fuel supply pump, or as simple as corroded wire connections.
 
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