Ecutalk And Fuel Consumption

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Just trying to diagnose some possible running rich issues. After replacing my 02 sensor, my town economy increased slightly (down to 12.5-13L/100km) but my 96 stagea still was using 12.5l/100km on the freeway which seems odd. I figure its running rich since theres tailpipe soot, and the exhaust pops when you rev it in idle.

Now to the ECUtalk oddity: it has a overall trip litre/100km measurement which is always optimistic. eg if I used 12.5L/100km, as measured at the fuel pump, ecutalk will read 10L/100km.

So where is the fuel consumption measured from? Could this contribute to too much fuel being injected?

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Actually on second thoughts the tailpipe soot isnt as bad as I thought it was. Nonetheless, still have concerns.

[Moodles2]

Ecutalk from my experience uses injector size and injector duty cycle to calculate fuel consumption.

As for consumption itself, get yourself a wideband AFR kit or borrow one. Will tell you how rich is it really running.

[mad082]

yeah ECUtalk calculates the fuel economy based off injector size and ecu mapping. if your economy is worse than the ecutalk is calculating then either the fuel pressure is higher, or the injectors are fouled (being fouled doesn't always mean it will be injecting less fuel. it can mean that is actually injecting more fuel as the injectors may not close properly, etc).

the other thing that may possibly be causing the oddity is that the odometer might not be working properly, so the KMs you are using for the calculation are actually more than what the ecu is reading (and what you are actually doing). if you, or someone you know, has a gps, use it to keep track on the distance you go between fill-ups (most will have trip logging. in the case of most Garmin ones, just tap the speed window on the map screen and you can reset trip totals from there).