1982 series 3 xj6. Does anyone else experience their gas gauge finally reading correctly after the car is warmed up and is at operating temp? It reads low and gets higher as soon as the car hits the temp

 

no I have not experienced that symptom in my '84.

I am starting to wonder if you have some crossed wires at the gauges, have you downloaded the Service Manual and checked all connections one by one?

 

I don't know if XJs have a gauge voltage stabilizer, like E-types have, but a bad voltage stabilizer could cause sluggish fuel gauge readings.

 

The gauge works it just works slow. After the car has been driven a little bit the gauge finally goes up a little more. Where are the wires I can check and clean? Can you simply pop out the gauge on the dash?

 

Sometimes the gauges are a bit lazy. I've seen it on several Ser III cars, including the one in my garage right know. Most often it's the voltmeter but it can be others as well.

However......it certainly shouldn't take as long as waiting for the engine to warm up.

Check connections and grounds!

Cheers
DD

 

make the following maintenance procedure > not that it might resolve anything, but it will be a learning exercise and keep you busy:

0) disconnect Negative Cable from Battery,

1) remove the tail lights Lens, (4 phillips/pozi drive screws)

2) remove the tail lights housing, (3 large phillips screws)

3) disconnect the wiring plugs and place assembly safely away

4) look inside the fender with flashlight where you will see the rear of the gas tank,

5) you will see electrical wires connected to the Fuel Sender,

6) remove each wire (one at a time) and clean the connector terminals with a brass wire "toothbrush". You must not produce "sparks" while doing this, that's why you use a brass brush.

7) do the same to each wire connector and connect the wire back

8) reassemble the tail lights and go to the other side and repeat.

9) when finished, reconnect Battery Terminal and start engine.

 

Is the clue, "being driven a bit", rather than warmed up?


sloshing in the tanks causes the lever to go up and down just a tad. that in turn wioes the little rheostat that creates the signal to go forward to the guage. if the surface is abit grungy, it would not respond nicely.


The guy next door was fixing a non responsive guage in a middle aged Ford van. It uses a pump sensor combo. Neat lttle rheostat. Badluy worn pivot, so the contact of the sweep and fixed was non existant.


Yuk no fix, new unit only service. Were it mine, I'd seek to find a way to tighten the pivot and eliminate the wear.


The unit in the tank is the ground. so, it has variable resistance to send to the guage.
electromechanics at work.


Carl

 

Yikes. I bought two tank gauges for this 77 XJ12 I am working on. I have referred to it as mine but it's a pals and it's been here for a few months (about 20) .

I am going to try the contact cleaning procedure armed with your insight before I pull the gauges. The right tank gas gauge just sits on 5/8ths full. I suspect it's stuck but I have the fender skirt off on that side and access is relatively easy for a clean up.

Thanks!

 

I can't say cleaning those contacts is going to resolve the issue with your '77, I was talking about the Series 3 XJ-6 Fuel Sender/Float assembly wires which are connected at the rear of each tank in the 1980-1987 XJ-6/12.

I am not familiar with the Series 2 tanks, Senders, or Floats.

But you bring up something interesting: A sluggish FLOAT or one that doesn't rise fully when the tank is full might cause the 5/8 symptom you are experiencing.

In that case, I would remove the float assembly. inspect it and lube it with some kind of thin lubricant, like 20W carburettor oil.

I did that to the floats in my '65 S type tanks and it fixed one of the floats that was rusty and almost stuck in place.

the gas tank floats are the same principle as toilet valve ball floats, the difference is they are submerged in gasoline, not water. Both get rusty and get stuck.

Remember when removing the assemblies from tanks you need a brass punch/chisel and a plastic mallet, never use steel tools, it can cause a spark and potentially an explosion

 

Many thanks.

I purchased two new floats from John's cars last summer. I am replacing them both. They were around $110 for both.

I will be careful with the job and will take some pics. Bet they are not that different from the "newer" ones.