xantia 2.0 hdi fuel guage

[xantiasmiff]

Its been a while since i last posted here so hello to everyone. I have replaced the low pressure pump and sender unit in the tank 3weeks ago due to failure. (3rd time in 4yrs). Recently, the fuel guage dropped to empty with fuel light on, although there was about 3quarters of a tank in it. Have replaced instrument dash with a working second hand one but still no luck. Any ideas please.

[rory_perrett]

Interestingly I had the same thing. 1st, just as a slight aside, ever since I got my car 18 months ago I have had a problem with the fuel gauge, sometimes it reads right sometimes it reads full regardless of what is in the tank. It is a fault in the instrument itself as tapping the binical can often get it to drop to right reading.

OK then just before xmas I had to fit a new lift pump. Used the fuel, light comes on, go to fill up and when I get back in the car its still reading empty and the light is still on.

Tried thumping the top of the unit a few times, no joy. No problem I thought I'll just swap the sender unit with the one on the old pump unit as that was working fine. Unscrewed the holding ring, jiggled the unit a bit and straight away the gauge starts reading right. Still on that tank full of fuel so don't know what will happen at the next fill-up but I'm wondering if the position of the sender/pump unit is critical and when the tank gets empty the float can drop down and catch on the inside of the tank somewhere if its not positioned right.

[Xantidote]

If you've replaced the dash unit with a good unit, then it has to be either a faulty sender unit in the tank, a poor connection in the connector on the top of the tank cover, or a break in the wire from the connector to the instrument dash.

Maybe you've disturbed something whilst replacing the pump? I'm assuming the pump itself works, and car otherwise runs OK.

First off, think I'd be looking closely at the connector and it's wiring, that being the easiest & simplest. Being a S1, my car's not quite the same as yours, but Haynes shows the connector on your tank cover as being brown, 5-way. IIRC, my connector has a number moulded into each line in/out of the connector. For your fuel gauge connector, Haynes shows No. 5 going to earth, and No. 1 going to No. 1 on the instrument panel, this latter wire having the number 432. I'd try a jump lead to bypass/replace each, in turn, to see if that sorts it. Alternatively, use a meter if you have one.

With a bit of luck, some other forum member will be along to tell you what voltage to test for at a specific point, or pinpoint where the fault usually occurs.

Good luck

Edit: I see Rory's got other advice on subject - perhaps more relevant

[xantiasmiff]

Thanks for the replies and suggestions guys. The gauge stopped working about a week after the new pump/sender unit was fitted . It faded gradually over 10 to 15 min period from 3/4 to empty. Car working normally apart from this. Anybody else had this problem and managed to fix it?

[xantiasmiff]

Anybody else had this problem. Please help if you can. Thanks.

[rory_perrett]

Small hole in float, now full with diesel and no longer floating perhaps. I suspect you are going to have to take the unit out of the tank, check it over and get a multimeter on it to see what it reads as you move the float up and down.

[xantiasmiff]

Just thought id give an update on my fuel gauge. ITS WORKING !. I put off checking it again, due to bad weather and long hours at work. Anyway , set off from work last thursday and the needle on the gauge started rising ! Its now working, but for how long?. Is this citroen electrickery in action?

[Krede]

My fuel gauge (X2 HDI) will often drop to "empty" when about half the fuel is gone. The "bingo fuel" warning light does NOT go on however (I know the light works)
I haven't tried to remedy this, but I suspect the sender unit is faulty