When I shut the car off the fuel gauge isn't returning to empty. It stops on random spots on the gauge, then when car is started, the gauge increases from that spot.

any ideas will be appreciated. This is a '97 convertible

 

Not just a ‘97 issue. Many of the early cars, including my 2002 XKR have problematic fuel level sending units. Some act up like yours. Others, like mine, have their own inaccurate idiosyncrasies .

Very common in many older cars, not just Jaguars.

but unlike most, our sending units are a bi*ch to replace. So poor accuracy endures.

I find that on long trips, the vibration and / or the constant tank refilling, serve to “free up” the sending units considerably. And it becomes quite accurate. Until the car sits for a few days . Then it’s back to normal.


Z

 

If the problem is that it doesn't return to zero when the ignition is off, I don't think that would be a sender unit? I would start with a hard reset to see if that helps, but I've had the same issue with the temp gauge and had to pull the cluster out and return it to the stop by hand.

 

Thanks for the replies. I just bought the car and it was working ok. Then sometimes back to empty, sometimes to 1/4, etc. I haven't used the car that much but, come to think of it, the more I initially used the car, the gauge was working ok. Guess I'll just live with it and track the mileage for fill-ups.

 

When you say "hard reset" exactly what do you mean? How is that done? thanx

 

A hard reset is where you disconnect the battery and hold the now disconnected positive and negative cables together for a few seconds to reset all the modules. Don't do this if you need all your drive cycle monitors set for an upcoming emissions test.

I think I would just drive the car and hope the fuel gauge unsticks itself through use. Press the button on the end of the indicator stalk until you get the Range display on the dashboard - no need for a working fuel gauge when you know how many miles of range you have left. This will also prove if the sender is working ok and it is in fact just the gauge.

 

Note ; “ miles to empty “ will not be accurate if the sender has a fault and the gauge not displaying correctly .

But the “ gallons used “ will still be very accurate.

at least that how it is on my 2002 XKR.


Z

 

This is the hard reset procedure that I copied off of this forum when I first bought my car years ago.


there may be other variations but this is the one I use:

HARD RESET PROCESS:



HARD RESET



Remove Negative Battery cable from the Negative Battery Post (10mm Wrench)



- Turn ignition key to on position - this provides a mechanical link to circuits that are isolated



- Turn off ignition



Touch Negative battery cable end to Positive battery cable end and hold there for 30 seconds



(Positive cable will still be connected to Positive Battery Post). When you touch the negative cable to the positive cable on the battery, there should be nothing at all hooked to the negative terminal.

Touching the disconnected negative cable end to the positive cable will short-circuit the supply rails at the ECU's & modules to discharge the internal capacitors. Any electricity stored in the electrical system drains out through the negative cable and into the chassis. The reason to drain the capacitors is THEY still have a complete circuit on the car so you are giving their positive terminal a path to ground to discharge them.



- Turn ignition key to on position



- Turn off ignition



Reconnect Negative Battery cable back to Negative Battery Post



- Start the car



- Let it idle for about 10 Minutes



It is normal after disconnecting the battery that your RPMs will be high when restarting your car and your acceleration will be very brisk. This is part of the ECM learning process and on your next start up it should be at normal levels. This is like doing a full restart and your car will be forced to learn again - you can also temporarily remove SOME stored problem codes this way.

 

Thanx for the responses. They've been a big help