Had my fuel pump changed. Before my out of fuel light came on exactly on the minimum fuel line (0). Now my reserve light comes on before the minimum mark line see photo.

Why is this so?

Can I calibrate this or is this part of the new pump.

 

Might be that that put the stuff back in wrong and it's binding. It happened to me once. All I did was twisted the hat on top I believe.

 

Don't recall the low fuel level warning light coming on at the mininum fuel level (0) mark.

Best I can tell it comes on when there is around 60 miles of fuel remaining.

With the Turbo there is no fuel level mechanism to report the fuel level below half a tank. The fuel tank is split into two basins. The basins are not connected at the bottom and for each basin there is a siphon jet to pull the fuel out of the basin.

Once the fuel level drops below around 1/2 tank the on-board computer calculates the fuel level based on how the car is being driven. One can see the computer play with the numbers if he switches the display to show the miles remaining and then adopts a high miler driving technique. The miles remaining can actually go up instead of down.

Not sure what you can do about the fuel level warning light coming on at a different fuel level than before. Maybe you are driving the car differently, perhaps more aggressively, and the computer is tripping the level fuel level warning light a bit earlier than before because of this?

 

I've filled the tank at the point the photo was taken. I've managed to squeeze in 50 litres. This means 14 litres was still in the tank considering our tanks hold 64 litres. As per Macster this makes sense as I average 13.5 litres per 100km (60miles). It seems all is ok then. Can anyone recal their analog fuel dial position as the low fuel light comes on? Are we saying that this can vary per driving style? So, if you drive your car gently the dial will drop further before the warning light illuminates? Huh!

 

My analog gauge has always illuminated with low fuel warning when the needle is about the same position as the photo in the original post. Also like clockwork happens to coincide with 50 mi range remaining, which further confirms the gauge position and mileage remaining counter are connected below a certain point.

 

This is very useful information! This must explain how I once managed to run the tank dry half way through a 20-minute track session despite reading 1/3 tank at the start. Moral of the story: don't trust the gauge below 1/2 in atypical driving conditions.

 

Also, I've noticed if your tank is nearly empty and you only put, let's say, 20 litres of fuel in the tank, the needle won't register any fuel being added. It made me go to the petrol station attended when this happened questioning the pump fuel delivery. I am convinced he thought I am a total idiot. :-). I always fill up to the top now.

 

My recommendation would be one shows up at the track with as full of a fuel tank as possible. And filled up with race gas with the tank as low as reasonably possible, too.

Or if there is a race fuel pump at the track to after a run bring the level up to around 1/2 tank or a bit more just to add cool fuel to the tank. Running the A/C except during the track hot laps can help as this cools a fuel cooler.

While a full tank brings with it a penalty of weight -- albeit over the relatively light front end -- it helps the fuel pump run cooler and keeps the siphon jets totally submerged and helps ensure the fuel pump doesn't ingest aerated fuel. Might not hurt the fuel pump but I worry about any real change in delivery fuel pressure. And running out of fuel.

A hard working Turbo can really drink the gas. I would not be suprised fuel mileage would drop to the single digits. Heck the real time instantaneous fuel consumption display of my 2006 GTO (6.0l 400hp V8) would drop to 6mpg when I got on the gas hard and that was just a brief hard acceleration on the street.

No instantaneous fuel consumption display like that with my Turbo but if I want to visit a gas station all I have to do is thrash the engine some and the fuel tank levels drops precipitiously. A hard working Turbo engine is a thirsty engine.

 

Me too.

 

Gr8. Thanks. All normal then. Solved! .

 

I didn't read the whole thread, but you can recalibrate the fuel gage. First completely fill (19 l) the tank. Then disconnect the battery for 15 minutes (or so). Once re-connected the fuel gage will be recalibrate automatically.

 

Ok. But some of us have established that the fuel gauge and fuel warning light seems ok as per photo I've posted - see beginning of the thread.

Also you've probably meant fill the tank (64 litres not 19) right?

 

I have not heard of gauge recalibration but I wonder if that is what happened and why your gauge reading has changed with the new pump.. Certainly the battery was disconnected for that type of work

 

Definitely battery was disconnected when the pump was changed. Can't recall if my tank was full at the time. But considering two guys here say that their fuel warning light coming on and their analogue dial position reads the same as mine in the photo probably means all is normal. Perhaps calibration was off before the pump change? Don't know. Wired.

 

Yup, mine also matches the first pic for when the low fuel light comes on, with 60 miles remaining on the range-o-meter.

That said, now I have larger (1000cc) injectors. The fuel gauge seems good for the upper 1/2-2/3 tank. But I cannot rely on it for the last 1/3 tank. Likely because of what Macster brings up that it is calculated...likely by injector time. I've run dry on my way to the gas station, with 28 miles remaining on the range-o-meter. As far as I know, there's not way to calibrate this for the larger injectors.