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aftermarket fuel pump vs. fuel comsumption
hey guys, I've stumbled on something VERY weird...
Since i installed my walbro fuel pump, ive noticed a definite increase in fuel economy...
instead of before i was getting 420-440kms per tank (i know pretty terrible - my cars untuned so thats taking its toll - im running quite rich). but since i did the pump, im getting more like 450-470kms. no lie, ive always closely monitored my fuel consumption, one of the ways i can tell if my QR is still trouble free.
Its nothing to do with fuel pressure, cos that would lead to more fuel being injected, and i havn't noticed a jump in power (or a loss for that matter).
the only thing i can think of is that its supplying the fuel to the rail more efficiently. so neither the pump, injectors or computer have to work as hard, but there almost no possible way they would make a 30km/tank difference!
Any ideas?
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31/Aug/2009, 1:46 am
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Re: aftermarket fuel pump vs. fuel comsumption
Hi Cam,
The amount of fuel used (and hence economy) is a factor of a few things ...
- pressure
- length of time injector is fired
The length of time the injector is open is effected by ...
- amount of load on the engine (more load, more open throttle, more fuel)
- octane rating (higher octane, more energy, less fuel required for engine load)
- intake pressure charge (more air, more fuel for standard air/fuel ratio setting)
Now I don't think our ECU monitors the exact fuel microlitres injected per cylinder by a flowmeter so I think it will be a purely timed opening based on throttle position, air volume, cam timing (fuel flow has to stop when intake valve starts to close) and exhaust oxygen content (air/fuel ratio monitoring).
Your gain is only about 10% or slightly less so I think it might only be driving style.
Didn't you say a while back you had to take things easy for a while until you get it all together and tuned ?
--- 
Kev X450(c)
2003 Titanium Ti Luxury Series 1 |
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31/Aug/2009, 8:29 am
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Re: aftermarket fuel pump vs. fuel comsumption
Cam
I don't think the ECU can regulate voltage on the fuel pump.
It will constantly stay at 12 volts.
The only way I think it might work is the time the fuel pump is made to work.
ie, more power, the fuel pump increases pressure to the motor.
--- Tony X-891c
2008 T31 St
HERE is my X Trail
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31/Aug/2009, 4:49 pm
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