The most unreliable part of a Z – Part 2
I referred in the last edition about an unreliable item of the dashboard. The item in question in this articles is the fuel gauge, designed to provide the driver with information regarding the supply of petrol, it works by registering the variable voltage that is sent from the float inside the fuel tank, the variable resistor send a specific voltage according the amount of fuel left, the gauge displays with a needle that will point anywhere between the full marker and the empty marker.
The problem is that unlike modern gauges which are unerringly accurate, older fuel gauges never show a linear reading, they often read ‘full’ for 250 miles and then drops from full to empty over the next 50.
Mine is even worse, often it doesn’t read at all, then every so often it comes alive. This is due (I believe) to loose connections at the fuel tank.
However, being the resourceful kind I have successfully managed the usage of my fuel for the past 11 years since the build and for 8 years after my initial purchase by measuring the mileage between fill ups. Never has a trip meter been used so much or has been such a critical device on the dashboard.
This ‘back up’ method has proven quite foolproof, just a couple of rules to adhere to and it works just as well a the gauge.
Rule No 1 : Make sure you reset the trip meter every time you fill the car up.
Rule No 2 : Don’t drive further than 250 miles before filling up again, actually keep it below 225 miles will take into account any spirited driving
This is never caused any issue in all the miles I have driven, some 20,000 trouble free miles, even Germany last year it worked a treat. With this as a backup I had not need for a fuel gauge.
That is until this year, actually it started last year when I last filled the tank. I didn’t reset the trip meter.
But that was OK because on my to-do list I was going to investigate and repair my fuel gauge so I could start using it in the way it was intended.
But of those of you who remember we had a rather large bit of wood that put paid to any work I was going to do on MBP that winter.
In fact, I did little more than wash it and MOT it before my first show in July. Silverstone Classic is one of those shows you really don’t want to miss. It has everything you could ever want, great cars on display, fantastic racing and brilliant music.
So with the car freshly washed and road legal, Sandy and left I early on the Friday and cruised up the A34. I was remarking on how well MBP was running when…… it went onto 5 cylinders and then it died all together.
Fortunately, a lay bay was some ½ mile ahead and I was able to cruise to a halt in the lay-by. I checked the trip meter but that only read 180 miles, so I must have enough fuel if I adhered to both rules, right? Bugger!
So, after a 5 mile round trip I was able replenish MBP with a gallon of 98 octane and it fired up immediately. Our 90 minute trip turned into a 4 and half hour epic journey, much to the mirth of everyone who was already there.
So there you have it – The fuel gauge is a really unreliable instrument in the dashboard, but unlike the clock you’ll only be unable to tell the time, when the fuel gauge fails, the car fails and when the back up plan fails then the most unreliable part is the bloody owner!