trip computer fuel consumption source

[Matteh]

hi

Bit of a lurker really, I usually stick to the clio forums

I've just been having a read through the wiring for the R19 trip computer (with the digital fuel gauge, mpg etc...) and was just wondering where exactly it got the info of fuel consumption from. I can see how it gets the speed and fuel etc no problems.

If I read correctly, it needs a pulse for every 80mm^3 of fuel fired - is this just supplied by a pin on the ecu, or from measuring the injector pulses or something?


sort of related, but was it all pre 94 models that came with the trip computer? are all the trip comps the same? which models of the R19 had it fitted... and how much do they normally go for


sorry for so many questions

 

[InSaNeBoY]

hi

Bit of a lurker really, I usually stick to the clio forums

I've just been having a read through the wiring for the R19 trip computer (with the digital fuel gauge, mpg etc...) and was just wondering where exactly it got the info of fuel consumption from. I can see how it gets the speed and fuel etc no problems.

If I read correctly, it needs a pulse for every 80mm^3 of fuel fired - is this just supplied by a pin on the ecu, or from measuring the injector pulses or something?


sort of related, but was it all pre 94 models that came with the trip computer? are all the trip comps the same? which models of the R19 had it fitted... and how much do they normally go for


sorry for so many questions

Think it's measuring injector pulse/duration. But that's just a guess. my '85 fuego has something similar MPG seems to be close, but way off on registering the fuel in my tank(seems to think my 12gal tank holds 15gal) :mrgreen:

 

[Chris H]

pulsewidth and road speed.

The computer was originally in the 21T then used in the espace, 19 etc.

Models after 94 had the trip comp as well just most are execs after that and they never got the digi display.

I have digi dashes etc if your interested, I also have just the digi display on its own if you want to mount it in the clio dash.

 

[Matteh]

oh cool! so you just connect it to one of the injector feeds?

what is a digi dash? will probably just go for the display on its own as it looks swappable with the clio. though would I be right in thinking I'd need a new wiper arm as mine doesn't have the cycle buttons and possibly a new trip reset needle?

 

[InSaNeBoY]

pulsewidth and road speed.

The computer was originally in the 21T then used in the espace, 19 etc.

what did those look like, separate box? one on the fuego does MPG, distance traveled, distance to empty, average speed, remaining fuel, time, outside temperature.

it's the display in the center stack above the vents.

 

[JR]

heythe kid's trying to hot-wire the car! can't even reach the pedals

 

[Chris H]

no it needs to be done through the ecu, the ecu has a digi dash output pin as the ecu does the calculating internally, from the road speed input and the injection parameters.

The display its self is reffered to as the digi dash. The orange glowy thing with numbers on it :roll: The reset is on the trip knob, its just a make then break switch to reset it. The same for the button to cycle the functions.

Insaneboy the display is not seperate like the fuego, its incorprated into the dash display itself. It has the same functiosn as you list, avg speed, distance travelled, avg consumption, distance to fill up, fuel level, outside temperature etc

The clio 16v has a similar display but it only displays outside temp.

19 16V ph1 dash display



clio 16V

 

[hooverphonique]

how much is needed for converting my 19 16V to digi dash except for the dash itself and the stalk with a knob on it? As far as i can tell, my wing mirror already has the temp sensor..

 

[Chris H]

the dash plug will be there most likely hooverphonique, it will be tucked away int he loom, green plug and a smaller black plug for the reset switch.

just the display and wiper stalk

 

[Neal R19]

i think the level sender in the tank is different too.

 

[Chris H]

yes it is, i forgot about that

 

[hooverphonique]

hmm.. thanks, guys.. the level sender is the biggest issue then, i guess.. is it part of the pump assembly?

 

[Chris H]

no its seperate you access it through the hole in the boot floor

 

[Matteh]

no it needs to be done through the ecu, the ecu has a digi dash output pin as the ecu does the calculating internally, from the road speed input and the injection parameters.

ah ok, I was just getting confused as the renault PDF I have shows the trip comp (digi dash) as having inputs for vehicle speed, fuel consumption, fuel remaining and temp

The display its self is reffered to as the digi dash. The orange glowy thing with numbers on it :roll: The reset is on the trip knob, its just a make then break switch to reset it. The same for the button to cycle the functions.

I assumed digi-display would be the trip computer unit and a digi dash was some kind of awesome all-digital instrument panel .

I've read about ways to reset the trip computer that involve turning a 'dial' to the right, I figured this was the needle on the odometer, is there a separate one?

The clio 16v has a similar display but it only displays outside temp.

19 16V ph1 dash display

clio 16V

cheers for those images! Fitting one to a clio 16v is exactly my plans.

temperature, vehicle speed and fuel level all seem pretty straight forward, just was puzzled over the source for the fuel consumption. but if it's all calculated in the ecu then it's a moot point anyway

to make things even more complicated, I'm running an F4R :lol:

 

[Chris H]

we already established that, it gets the inputs from the ecu. The road speed sensors connector is att he dash but it goes straight to the ecu then back from the ecu to the digi dash.

The reset is on the trip knob and you turn it to reset the computer. You push it in to reset the mechanical trip.

 

[Matteh]

the trip comp just requires a pulse signal from speedo cable, so couldn't you just wire the feed straight in?

I would need a new reset needle too, as the clio one just spins (though making the push to reset bit is simple enough)

 

[InSaNeBoY]

HA the back of that trip computer, connection and all look just like mine


and the pictogram and what not on this is exactly the same too, just in green As I recall the entire gauge cluster is very similar to the fuego, wonder if i could just swap one of those in... that's be interesting... (of course the fuel level is off on mine so maybe not such a hot idea)


big suckass for me though is I've got the bouncy speedo thing going on, and if it's the cable I can only get one that bypasses the speed sender Almost hoping it's the speedometer head that's dead.

 

[hooverphonique]

i think the level sender in the tank is different too.

Do you know if the digi dash sender will work on the existing rear loom

 

[Chris H]

it will the digi dash sender has another pin wired up.

 

[Matteh]

think I've got the above sussed now...


one last question, the digi dash has a constant live, does anyone know how its fused?