XJS V12 Instrument Readings

[GriffinNo2]

The gauges on my 1988 V12 read consistently low. The fuel gauge never shows more than 3/4 full, even when the tank is overflowing and the oil pressure gauge also seems to read consistently low. Any ideas anyone?

[jagtech]

I wouldn.t say they are related both are common issues with the xjs i suspect the fuel tank sender unit and probably the pressure sensor

[nigel1]

You could try adding an extra earth cable to the instrument cluster circuit board, that has been known to improve things

[kelsham]

I would agree that the two problems are unrelated. As suggested try a separate earth to the back of the instrument cluster. Who knows it may cure both faults.

I suspect that you will need to drain the tank low, shouldnt take a very long drive should it? Then remove the gauge sender from the boot. it is easily reached.

The likely scenario is that the sender float will be partly filled with petrol. Otherwise the sender may need to be dismantled and cleaned. The sender is held in with a ring that will need rotating. use a piece of wood and a wooden mallet. Sparks are to be avoided.

The oil pressure gauge often reads low due to a faulty sender, both XJS cars I have owned have needed replacing

regards Kels