Tdci Mk2 fuel gauge accuracy

[richard3009]

Just ran out of fuel luckily on my drive fuel gauge showing just under quarter tank with no fuel warning light, is this common?

[richard3009]

 £47 filled it to the brim is this an empty tank?

[Proautocare]

Welcome to the world of Ford fuel gauges, they're famous for doing this.

[jmurray01]

Yep!  Our previous MK1 could usually get down to empty on the gauge fine with no adverse effects (my mother has a tendency to keep driving and not even look at the gauge until I fill it up), but one day with the needle above the empty mark and low fuel light not illuminated, it died on the driveway and wouldn't restart.  Turns out it had ran out of fuel, despite the gauge still showing a positive reading.

That said, for your situation I'm dubious as £47 would not fill it to the brim from empty, as it is a 55 litre tank (at least on the MK1s anyway) which would cost around £66 to fill, depending on the price.  £47 would only get you around 40 litres, so even if you put 5 litres in from a jerry can that still leaves 10 litres unaccounted for. 

[richard3009]

And that's the bit that worried me having said that it was a classic out of fuel restart it tried to start then eventually carried off the starter into life. Done 5 or 6 journeys now without issue, but where was the 10 litres unless Tesco pump calibration is a mile out in my favour. Could be another issue here on the fuel pump.

[richard3009]

Just ordered a new cam position sensor to be on the safe side. Can I just swap it

[Tdci-Peter]

12 hours ago, richard3009 said:

Just ordered a new cam position sensor to be on the safe side. Can I just swap it

Yes, I am 99% certain you can just swap it.

If a 1.8TDCI really had run out of fuel, and got a good dose of air into the Diesel pump, then in my experience, it would never restart on the starter motor. It would need priming (ramming fuel into the pump), or maybe a tow start with a lot more than the 200rpm you get while cranking. (Though whether this is good treatment for a dry pump & dry injectors, is open to discussion!)

Coupled with the lack of fuel added, it suggests another fault. But with lack of symptoms & diagnostics, it is hard to guess what. Maybe a little bubble of air got in the fuel, not enough to allow the 1st stage of the diesel pump to run fully dry, but enough to cause a glitch.

[richard3009]

Just as a side note prior to the engine cutting out I had the noise of what sounded like a dry pulley in time with the engine revs, it's now completely gone, I had the fuel filter changed a week ago and wonder if some trapped air has finally made its way out of the system.

[Tdci-Peter]

6 hours ago, richard3009 said:

I had the fuel filter changed a week ago and wonder if some trapped air has finally made its way out of the system.

It is very difficult to refit the fuel pipes without getting some air into the top of the filter. I have fitted a nice non-return valve to the pipe going to the filter. Now, I can prime from the inlet side of the filter, then remove the priming system, keep the pipe and the filter inlet topped up with fuel, and refit the pipe to filter with almost no air at all entering. The photos below show it, first being put in to the pipe to the filter inlet, then with the priming system. Not very clear, but the valve is at the bottom left, and the transparent hoses go from this inlet pipe to the filter inlet port via the bulb.

Lets hope that is what is was. The odd noise might have been to do with the pump, maybe the volume regulator solenoid was operating rapidly to deal with the air bubbles or something.

[richard3009]

Cruised 30 miles to work 3 times without a blip, so touch wood it's stable at the moment.