Tarzan

I am looking to install a meter that would tell me the fuel economy, something, that plugs into the input and return lines and subtracts one from another to show how much fuel gets disbursed thru the injectors. Is this realistically doable?

Matt93SE

iTrader: (44)

doable? sure..
but not for less than the car is worth.
you would be better off to look at the MAFS sensor or fuel injector pulses and do a summing calculation based on the total amount of air or fuel sucked into the engine over time.
then use the odometer or speed sensor to do a summing function for distance and that would give you fuel used and distance travelled.

not something the average joe could build though. lots of assembly code to stick on a chip.

Tarzan

I am not an average Joe , but now I am puzzled as to how a ****ty VW Rabbit had an accurate trip computer back in 1988?

Slamnasty

GXEs don't have trip computers? My 93 SE has one...

disgruntled

iTrader: (7)

check with the 2nd gen forum, I believe that on some of the 2nd gen model , Nissan had actually implemented a trip computer that tells you how much gas you got left in the tank, the mileage on the tank, and the amount of mileage left that you can travel until the tank is empty. They really went electronic crazy with cars back in the 80s to early 90s, hence all the electronic speedometer on those year model, check out a BUICK or CADDI and you will know what I mean.

Tarzan

I am rather interested in momentarily information of the fuel consumption, than what's left in the tank.

twinkle

iTrader: (1)

i think that thinkgeek.com used to sell a universal one

twinkle

iTrader: (1)

http://www.thinkgeek.com/gadgets/electronic/72fc/

found it ^

twinkle

iTrader: (1)

nevermind im an idiot, those are only good for obdII cars

Slamnasty

OK maybe I'm mistaking a trip computer for that odometer-like dial on my dash that only goes up to 1000 and the resets back to zero...

Tarzan

I know that when you floor like '95-'98 SAAB turbo, its fuel economy bar jumps into red area at the top, like 20+ liters /100 kms. That bar is an electronic display on the car's conventional dashboard. If they can put such an instrument into the passenger car, there should be a way to replicate it...

Matt93SE

iTrader: (44)

all that is is a manifold pressure gauge.
the lower the vacuum in the engine, the better your mileage is indicated. when you hit boost on a turbo car, your gas mileage does go to crap.