fuel milage display. how does it work?

[berniescout]

how does it work? my gas gauge is erratic at best. typical sender unit problems. so where does the computer get the fuel use info? is there a transducer some where? miles would be from the tranny i assume. 97 blazer. when ever i pencil and paper a calulation it is always about 1 mpg lower than the display.

[BlazinMlew]

Sender unit that will sooner or later lead to a disabled fuel pump. Trust me I have been down that road (not fun)

As for your question I have absolutely no clue. Sorry

[BlazerLT]

Only calculate economy by miles driven divided by gallons used.

[berniescout]

I alway calculate the real way mpg=miles/gal used. been doing it for the better part of 42 years (since i've been driving). the on board mileage computer is very close to the real ##. just wondering how it works. the mileage is obviously off of the tranny but i wonder about the fuel use. i know the main computer monitors a lot of engine functions, but how does it even estimate the fuel use?

[BlazerLT]

Originally Posted by berniescout

I alway calculate the real way mpg=miles/gal used. been doing it for the better part of 42 years (since i've been driving). the on board mileage computer is very close to the real ##. just wondering how it works. the mileage is obviously off of the tranny but i wonder about the fuel use. i know the main computer monitors a lot of engine functions, but how does it even estimate the fuel use?

I think it is a combination of factors it uses.

O2 sensor coubts, throttle angle, engine load.

[MT-2500]

As BlazerLT
Stated in his first post.
It watches the milage driven and the fuel tank gauge to get the gallons used.
Not real accurated but does give you a good idea as long as the fuel gauge and spedo is working right.
What does yours say or do when the fuel gauge acts up?
MT

[534BC]

Originally Posted by MT-2500

As BlazerLT
Stated in his first post.
It watches the milage driven and the fuel tank gauge to get the gallons used.
Not real accurated but does give you a good idea as long as the fuel gauge and spedo is working right.
What does yours say or do when the fuel gauge acts up?
MT

The fuel tank gage would not be quick acting indicator of mpg. The range can be calculated by the gage, but not instant mpg. I have heard the venture used "injector duty cycle" what ever that means. What ever it is is very repeatable and consistently off by 10% (on the Venture)

[MT-2500]

Originally Posted by 534BC

The fuel tank gage would not be quick acting indicator of mpg. The range can be calculated by the gage, but not instant mpg. I have heard the venture used "injector duty cycle" what ever that means. What ever it is is very repeatable and consistently off by 10% (on the Venture)

10-4 Different systems may be set up on different sensors.
When thay started using them things back in the 70's they just used a vacune gauge now they are getting more smarter all of the time.
It might be interesting to unplug the fuel gauge and see what it has to say.

MT