999.99 MPG

[Dumbclutz]

Hi, My computer has started to behave strangely (year 2000, V6 406 estate)
I ran out of petrol on the filling station forecourt !
So I put 35 litres in and the fuel gage displayed correctly, but the current MPG reading says 99999 and the elapsed MPG does the same. I can hold in the button at the end of the control stalk and zero these figures but they return immediately I wonder if there is some way of nudging the thing back to sanity? Or is it likely to be a dead fuel flow sensor (if there is such a thing)?
I have a feeling that the car didn't really run out of fuel, the computer just got fed up telling me that the fuel was low, and decided to shut off the pump,as the engine fired up instantly the key was turned after filling up, maybe I'm getting paranoid about it because I also keep getting air bag warning lights and the engine management warning light (the latter probably because the engine has decided to run on 5 cylinders, which I anticipate is the result of a dead pencil coil) On the last point, is it ok to pull off plug leads with the engine running, until I find one that doesn't make any difference to the engine running?
Cheers

[Tiny Tim]

I would have thought the pump would have primed like any other car once the ignition was on, so even if you had run the tank dry it would start up as soon as there was fuel there.

[Dumbclutz]

Hi Tim, yes of course you are correct regarding the pump priming once the the ignition was turned on, however my suspicion was aroused because the engine fired instantly the key was turned...no time lag for fuel to pump through. I had unsuccessfully tried for some time to start the engine on the forecourt prior to pushing it to the pump, without even a splutter, and so I was confident that there was no way the engine would fire up. Normally when a car runs out of fuel, a bit of bouncing while cranking the engine, will force some of the residual fuel through and re-ignite the candles for a short time. This car was dead, no asthmatic wheezing, just dead. I think that the sensor in the tank must send a signal to the engine to shut down, rather than the engine stopping running when it is sucking air. But of course I'm willing to be told otherwise, if someone knows how it works.
Of course, it would be better to keep the tank topped up then there would be no reason to worry.
I'm always driving around with half a pint in the tank and the plastic 5 litre tank in the back has been used on several occasions...at least I get some exercise that way!
Cheers

[andrew1608]

i would try and disconect the battery to allow a reset, i put a replacement door mirror on and the temp gauge did not function correctly, so i disconnected the battery and this allowed for a reset to be done, it's just athought.

[Dumbclutz]

Hi Andrew,
Thanks for the advice, I will whip the neg terminal off as soon as the day warms up.
Cheers