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Fuel Consumption.

dyken

By dyken,
in Engines & Forced Induction

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dyken Proficient

dyken

Posted
Posted

hey guys i got an r33 gts25 rb25de. usually to a full tank ide get an easy 450-500km.

pretty much used the whole tank today its sitting on the bottom bar and ive only done 299km.

any ideas as what could cause such bad fuel economy??

ive checked exhaust for leaks but there isnt any. the car has had no loss of power so ??? i dunno what it could be.

and yes ive tried the search but couldnt find anything

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https://www.sau.com.au/forums/topic/208426-fuel-consumption/
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Eug Grand Master

Eug

Posted
Posted
and yes ive tried the search but couldnt find anything

really?

http://www.skylinesaustralia.com/forums/Pr...uel+consumption

http://www.skylinesaustralia.com/forums/o2...uel+consumption

o2 sensor, service the car, maintenance, etc.

troubleshoot what you've changed recently. ambient temp can also have an effect.

dyken Proficient

dyken

Posted
  • Author
Posted

thanks eug for that.

my driving has not changed, i havent been driving it hard at all.

ill clean the afm. and check the o2 sensors. it shouldnt be to hard to change the o2 sensor myself shouldnt it?

and yes im useless with the search..

inthisglass Grand Master

inthisglass

Posted
Posted

if you do a search there is a cazillion topics on o2 sensors

basically they are meant to be changed every 40 thousand kms so its a good idea to get a new one

when i got a new one about 5 thousand kms ago my fuel went from 450 kms to a tank to about 530 kms a tank so its well worth it.

  • 2 weeks later...
Sandeep Community Regular

Sandeep

Posted
Posted

first thing is to check for fuel leaks, a clamp may have come loose somewhere in the engine bay so just check them to be safe. also check your coolant temperature sender for surface corrosion on the connector... if the ecu doesn't get a good signal from the coolant temp sender it may think the car is running cold and will richen up the AFR's. you can clean the CTS with a nail file, just need to remove any surface corrosion so that the sensor and loom connector have nice clean metal.

if O2 sensors and CTS checks out, check your fuel pressure regulator and also do an intake pressure test to see if you've got any vacuum leaks.

also try and get your car on consult or datascan to check for error codes.

TokyoTaxi Veteran

TokyoTaxi

Posted
Posted

After you've gone through all that, get your injectors taken out and properly cleaned and inspected ( condition & spray pattern ). Chances are, if you've done over 100,000Km the spray pattern and operation of your injectors will be less than optimal.

Just my 2 cents......

Sandeep Community Regular

Sandeep

Posted
Posted

have you tested your o2's? you can do it using a voltmeter or using consult/datascan. you just need to make sure they're nice and responsive and that the voltage output should sweep from low to high about once a second. datascan or consult is easiest coz it will just display the voltage output for you. just make sure your car is at operating temp and you'll need to rev to about 2000rpm when you're measuring the voltages.

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