Petrol guzzling / leak issues

[froggy]

Was going to work this morning in the van when suddenly noticed the fuel gauge dropping, didn't think much of it as i was going up a hill but when the road straightened out the gauge continued dropping. Panicing i turned round and went home to jump in my other car.
No petrol smells when driving, nothing through the heater vents, no signs of petrol leaks inside the engine bay, no drips under the floor when i got home, very very confused. Unfortunately by this time it was very dark so didn't have the chance for a proper look but concerned about what might be wrong.

Sorry for the little amount of info but anyone got any ideas?
The only thing i can think of is a cracked filter (but would expec fuel on the floor under the van) or maybe the fuel pump has cracked internally (petrol leaked into the engine)

 

[Loxy]

It should be easy enough to tell if there is fuel in the case by smelling the dipstick (& the level).
How much fuel was missing & how full was the tank when it started?

I had a problem with a new fuel hose that I fitted once where it leaked when under pressure but not enough that the fuel gauge would obviously drop (the external cotton braided type - replaced with internally braided Goodyear FI hose).

If no fuel leaks can be found then I guess some sort of electrical problem or could the float on the fuel sender have a leak & be slowly sinking????

 

[froggy]

Lost just over a third of the tank in about 20 miles.
Luckily not at work until tomorrow night so if the weather stays dry then i'll get out and have a play.
Like i say though, no visable leaks, no smell, no drips. Got a spare fuel pump in the garage if thats gone (hopefully its as easy as this to fix) but just confused :?

 

[Cali_bay]

Had a leak from a braided hose right by the fuel tank on ours about 2 yrs ago. It looked fine but closer inspecton showed it to be oosing. There was however signs of the leak on the floor.
Another possibility is the carb float shut off needle staying open. If this happens the float chamber will overflow and more fuel will go through the engine.

Hope you get it sorted.

 

[froggy]

Had a play and possible found the fault.
Drained the oil (just in case) and no smell of fuel or even copious amounts of oil which i would of expected considering how much petrol i lost, all fuel pipes dry and no leaks / wet joints, fuel filter still full of fuel with no cracks, spark plugs dry (a little black but no excess fuel) :?
Opened up the petrol cap and there seems to be alot of fuel still in the tank compared to what the gauge reads, so had a play with the wires on the back of the gauge and the single wire is loose, tight onto the terminal but the whole terminal is loose, next thing i know a fuse pops, change the fuse after trying to secure the terminal and now the gauge reads either full or just below a quarter so hopefully a new gauge will cure my issue.
At least i have now have a little more piece of mind that its not to serious and i also managed to do an oil change, clean and re-gap the sparks plugs, reset the timing and had a play with the carbs settings so not all bad, just froze my nuts off doing it. :lol:

 

[BJ1]

A loose top terminal is the most common fault on these gauges. It's just riveted on and after about 36 years of vibration it gets a tad loose. I've fixed several by carefully cleaning the terminal and the brass mounting then soldering the whole lot together with a heavy duty iron and lead solder. It's possible to do this while the gauge is still in the tank, but obviously a bit stupidly dangerous, so best to remove the gauge first.

 

[froggy]

Well ordered a new gauge and temporarily fitted it gauge reading full, re-fitted my old gauge and got no reading but still think i have another fault, possibly a short on the brown feed wire from the sender unit. Will run a proofing wire tomorrow from the terminal that comes from under the fire wall directly to the gauge to see what i get and take it from there :?

 

[froggy]

Had another play today and still no clearer as to what the fault is :evil:
Fitted the new gauge and getting no reading (empty) checked and got voltage to the gauge, got continuity across the gauge and got continuity from the brown wire to earth (according to the drawings i've got this is through the sender unit and then earthed) which means that either the float in the sender unit is stuck down OR its holed, either way engine out and petrol tank out :evil: good job i bought a new sender unit last year (just in case) but its going to have to warm up before i drop the engine so if you see a bluey / primered van on the hard shoulder its probably me :lol: