Author Topic: fuel economy gauge (Read 4923 times)

FreakRi · « **on:** September 24, 2010, 09:06:18 AM »

Hello everyone. I'm new here and I need some help.
I have little problem with my fuel economy gauge on my E30 M42B18.

When I start the engine the fuel economy gauge shows maximum consumption. Now my question is this. How do i fix this problem and make the gauge to show proper consumption.
The electronics and the coding plug behind the instrument cluster have been replaced with a new ones.

I f anybody had a similar problem could you describe me in details ho can i fix this problem.

YetiX · « **Reply #1 on:** September 24, 2010, 10:49:16 AM »

Do you mean that when you start your car and it's idling, the econometer is showing 0 mpg? If so, they all do that. At least every one I've driven did.

1991 E30 M42 · « **Reply #2 on:** September 24, 2010, 11:40:58 AM »

they all do that, when your engine is running and you aren't moving you are getting 0mpg

FreakRi · « **Reply #3 on:** September 24, 2010, 03:15:12 PM »

I meant when i start my engine the gauge shows a consumption of 40L and when I drive the car it doesn't move from that spot.

DesktopDave · « **Reply #4 on:** September 24, 2010, 04:12:37 PM »

That gauge gets a signal from the diff to calculate consumption. If the DME (fuel injector duty cycle) or diff signal isn't right it'll malfunction.

I had a bit of water in my diff sender connector a while back - it made the gauge go from left to right, never in the middle. The speedo and cruise also didn't work...all from one bad sender connection.

Do all your other gauges work?

Good to see a Croat here...my family came over from Gorsky Kotar a while back.

FreakRi · « **Reply #5 on:** September 24, 2010, 04:56:25 PM »

The other gauges work normal, only the fuel economy gauge doesn't work, the sensor on the diff i brand new and the wires are not faulty......

Does anybody have any idea what could cause the fuel economy to be faulty.