Accurately measuring fuel flow (2 litre petrol injection)
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- Purple Pixie
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Accurately measuring fuel flow (2 litre petrol injection)
Greetings
I have tapped into a source of supply of flow meters that can be fitted into fuel lines
HOWEVER as I understand it our injection systems have a feed line and a return line, with a meter in both lines showing how much fuel has passed through, the difference between the TO and the RETURN is the USED, taking this and the distanced travelled gives an accurate MPG
Now the question is how accessible are the lines to/from and what pressure are we talking? can the unpressured line to the pump and (unpressured?) return be tapped?
unpressured meaning not at injector rail pressure
Thanks
Dr B
I have tapped into a source of supply of flow meters that can be fitted into fuel lines
HOWEVER as I understand it our injection systems have a feed line and a return line, with a meter in both lines showing how much fuel has passed through, the difference between the TO and the RETURN is the USED, taking this and the distanced travelled gives an accurate MPG
Now the question is how accessible are the lines to/from and what pressure are we talking? can the unpressured line to the pump and (unpressured?) return be tapped?
unpressured meaning not at injector rail pressure
Thanks
Dr B
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- Simon Jones
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Re: Accurately measuring fuel flow (2 litre petrol injection
You could fit the flow meters at the tank end. That way you could get away without cutting the fuel lines.
- Purple Pixie
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Re: Accurately measuring fuel flow (2 litre petrol injection
Anyone decode which one goes where as there is probably:Simon Jones wrote:You could fit the flow meters at the tank end. That way you could get away without cutting the fuel lines.
- A breather
A feeder
A return
and others?????
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- Simon Jones
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Re: Accurately measuring fuel flow (2 litre petrol injection
This is from V6 but i would expect it to be the same. From left to right (in the previous photo) the pipes passing thru' the top plate are:
To engine
From engine
Filler neck vent
You can see the other end of the pipework here:
The pipe that runs over the top is probably something to do with vapour management and would not be relevant for your purposes.
To engine
From engine
Filler neck vent
You can see the other end of the pipework here:
The pipe that runs over the top is probably something to do with vapour management and would not be relevant for your purposes.
Re: Accurately measuring fuel flow (2 litre petrol injection
Hi Purple Pixie, sounds like an interesting project, what type of meter do you intend to use. The normal unit is a Duel flow supply and return, usually wee bit expensive.
Good luck.
Good luck.
- Purple Pixie
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Re: Accurately measuring fuel flow (2 litre petrol injection
They are rotary vane in-line meters with remote display units which are capable of taking inputs from multiple sensors, I am just trying to work out if they work at the low litres/hr levelrita wrote:Hi Purple Pixie, sounds like an interesting project, what type of meter do you intend to use. The normal unit is a Duel flow supply and return, usually wee bit expensive.
Good luck.
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- Simon Jones
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Re: Accurately measuring fuel flow (2 litre petrol injection
Are you going to take a feed from the speed sensor so you can calculate consumption per mile travelled? If you want to know if you are driving economically rather than an absolute consumption figures then a vacuum gauge on the inlet manifold would be the simplest option.
- Purple Pixie
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Re: Accurately measuring fuel flow (2 litre petrol injection
... vacuum gauge meets with my "Occams Razor" approach to solving technical problemsSimon Jones wrote:Are you going to take a feed from the speed sensor so you can calculate consumption per mile travelled? If you want to know if you are driving economically rather than an absolute consumption figures then a vacuum gauge on the inlet manifold would be the simplest option.
I am more interested in average consumption over a day or week.........
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1999 Ford Freda - "Purple Pixie"
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1999 Ford Freda - "Purple Pixie"
Re: Accurately measuring fuel flow (2 litre petrol injection
Mighty complicated way of doing average
Why not just brim your tank full to top and zero your mileage
Do your day / weekly mileage and then brim your tank again which will give you the amount of fuel you have used
You can even put these figures into a app thingy which does all the maths for stupid people like me
Think the app is called fuelly
Some peeps on here have it displaying on there pages
Why not just brim your tank full to top and zero your mileage
Do your day / weekly mileage and then brim your tank again which will give you the amount of fuel you have used
You can even put these figures into a app thingy which does all the maths for stupid people like me
Think the app is called fuelly
Some peeps on here have it displaying on there pages
Gas safe heating engineer / plumber if you need any advice just shout.
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Re: Accurately measuring fuel flow (2 litre petrol injection
Are you planning on using some form of data logger, or programmatical solution using something like a Pi or Arduino? Do the meters have a perpetual counter such that they record total volume of flow since day 1?
- Purple Pixie
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Re: Accurately measuring fuel flow (2 litre petrol injection
Meters have inbuilt batteries and a perpetual counter like a water meter - no embedded technologySimon Jones wrote:Are you planning on using some form of data logger, or programmatical solution using something like a Pi or Arduino? Do the meters have a perpetual counter such that they record total volume of flow since day 1?
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1999 Ford Freda - "Purple Pixie"
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1999 Ford Freda - "Purple Pixie"
Re: Accurately measuring fuel flow (2 litre petrol injection
Purple Pixie wrote:... vacuum gauge meets with my "Occams Razor" approach to solving technical problemsSimon Jones wrote:Are you going to take a feed from the speed sensor so you can calculate consumption per mile travelled? If you want to know if you are driving economically rather than an absolute consumption figures then a vacuum gauge on the inlet manifold would be the simplest option.
I am more interested in average consumption over a day or week.........
A lot easier and cheaper using the garage / filling station Pump and the vehicle trip meter.
Any extra you spend you get it in the tank.
- Purple Pixie
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Re: Accurately measuring fuel flow (2 litre petrol injection
Ah, agreed, but I am doing it for the hell of getting an end result that works!teenmal wrote:A lot easier and cheaper using the garage / filling station Pump and the vehicle trip meter..
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Re: Accurately measuring fuel flow (2 litre petrol injection
You need to ensure that the flowmeter on the supply is rated for EFI pressures, usually around 3bar, how are you estimating the flow rate?
If you have diagnostics then you could perform an estimate based on the injector pulse width.
If you have diagnostics then you could perform an estimate based on the injector pulse width.
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Re: Accurately measuring fuel flow (2 litre petrol injection
The pressure in the fuel lines is not going to be too great at the tank end (I would have thought) as it uses conventional rubber fuel hoses rather than metal pipework.