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Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Mon May 05, 2014 9:39 pm
by GreenBongo
Usually its a reinforced rubber hose, does it not have the pump in the tank?
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Mon May 05, 2014 9:42 pm
by Simon Jones
Yep. Just found this that suggests it can run up to 8 bar although 2 is average. This article mentions typical flow rate:
http://www.picoauto.com/tutorials/fuel-injection.html
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Mon May 05, 2014 9:47 pm
by GreenBongo
Then it has to push the fuel hard enough to pressurise the fuel rail, 3 bar is pretty standard for a Japanese EFI.
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Mon May 05, 2014 9:52 pm
by GreenBongo
That is interesting reading regarding the safety bypass, that would mean that you would need a flowmeter rated at up to 8bar maximum, although the working pressure would be considerably less. The main issue that I can see with that would be the fittings to the meters.
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Mon May 05, 2014 11:26 pm
by Purple Pixie
GreenBongo wrote:how are you estimating the flow rate? If you have diagnostics then you could perform an estimate based on the injector pulse width.
low volume flow gauge, absolute measurement rather than injector pulse width, assuming constant injector rail pressure I guess - how do you work out fuel volume injected, i suppose based on 14.7:1 stochastic ratio you could do some sums? but that would be related to engine speed (rpm) and not allow for any catchup time under load
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Mon May 05, 2014 11:45 pm
by Purple Pixie
The article is a generalisation: for an example, the 6R4 ran 2 pumps, one in the tank, a low pressure large volume and another in the front, a low volume high pressure. The unions in the photo don't suggest there will be any problems making connections up with Aeroquip type fuel line and unions.
http://thumbs1.ebaystatic.com/d/l225/m/ ... SdtCJw.jpg
No evidence of a pump in the tank suggesting it is en route... I might be wrong
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Tue May 06, 2014 12:59 pm
by Simon Jones
Purple Pixie wrote:No evidence of a pump in the tank suggesting it is en route... I might be wrong
It is on V6. See cylindrical object top right in my photo here:
http://www.igmaynard.co.uk/bongo/forum/ ... =0#p624639
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Tue May 06, 2014 1:07 pm
by GreenBongo
I can see the pics now. Those don't look like fittings that would be rated to anything like 8-bar, maybe it is just a lift pump.
Have you got access to a fuel pressure tester?
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Tue May 06, 2014 1:08 pm
by Purple Pixie
I've got an oil pressure gauge that I can sacrifice and tee it in....
John
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Tue May 06, 2014 11:14 pm
by Simon Jones
Look at the V6 schematics and there is no sign of any additional fuel pumps, so it seems there is just the one in the tank. The 2.0 may be different although I suspect the basic setup is much the same.
Engine:
http://lushprojects.com/bongopartsmk2/c ... mgno=.html
Pipework:
http://lushprojects.com/bongopartsmk2/c ... mgno=.html
Tank:
http://lushprojects.com/bongopartsmk2/c ... mgno=.html
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Wed May 07, 2014 7:22 am
by Purple Pixie
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Wed May 07, 2014 9:10 am
by mikeonb4c
Purple Pixie wrote:Simon 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.
... vacuum gauge meets with my "Occams Razor" approach to solving technical problems
I am more interested in average consumption over a day or week.........
This all sounds like using an problem prone sledgehammer to crack a nut. Why not just use tank top up to tank top up figures and get out and enjoy driving the beast. Or am I missing something?

Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Wed May 07, 2014 10:12 am
by helen&tony
Hi Mike...
Err...it's fun....LOADS of gauges to watch...so far I have 12, and another 4 planned...plus 2 screens ...one reverse, and one forward!....did I mention switches???....
Cheers
Helen
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Wed May 07, 2014 10:42 am
by mikeonb4c
helen&tony wrote:Hi Mike...
Err...it's fun....LOADS of gauges to watch...so far I have 12, and another 4 planned...plus 2 screens ...one reverse, and one forward!....did I mention switches???....
Cheers
Helen
I know, just being mischievous and giving peeps a reality check. My weakness is/was spending loads of time on mods for camping whilst only ever getting out occasionally to camp. Still that's the beauty of the Bongo: camping is only one of the many pleasures you can enjoy with it. Others include fitting complex fuel flow monitoring systems etc. ha ha.
Re: Accurately measuring fuel flow (2 litre petrol injection
Posted: Wed May 07, 2014 11:04 am
by helen&tony
Hi Mike...
You and Us the same there...still have to get out camping...haven't been for a couple of years....currently busy having just fitted front and rear dog guards, having had them cut and welded...finished the leather re-trim...nearly finished the door cards....stripped and cleaned the roof ready for a repaint, and the solar panel I bought off Dodgey to fit, along with some club-shop roof rails, and a spoiler to paint and fit!....just fitted the summer wheels, re-wired my flow meter (keeping in the thread here)...more wiring to do....just fitted a super-duper alarm system, and up-dating the rear-view with a 2-camera system...one for running, one for reversing....Oh...and fitting a second water/ methanol tank.....IF I get time, I have some thoughts on another "go-faster" system on the cards...MIGHT move house in the meantime, AND the Jeep needs a little customising!.....time for camping?????
Cheers
Helen