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I fixed my fuel economy..

predator

By predator,
in General Maintenance

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predator Grand Master

predator

Posted
Posted

Just a quick one.. thought I would share..

Basically replaced most fuel related items on my R32.. as I was getting absolutely terrible fuel economy - up around 15L on a stock boost/stock exhaust R32 driving around town, even though the car seemed to be powering along quite well.

Replaced fuel regulator, replaced oxygen sensor, replaced fuel pump, plugs, fuel filter. Not all necessarily just to improve the economy, just because I have been trying to fix a few other small things and generally servicing things.

Anyhow, had pretty much given up on it.. but I thought I'd give one last thing a try -- some injector cleaner. Have always been pretty skeptical on them as nothing more than snake oil in a bottle, and tried it a couple of times on other cars and no difference. But this time its seem to make a fair bit of difference.

Economy is now down to about 11L/100km highway, and 12-13L/100km city. Which is about a 2-3L / 100km saving.. which in the end means I'm saving about $2-3 every 100km.. not bad for a $10 bottle!

For what its worth I used Nulon injector cleaner. After 1 tank pretty much the improvement was obvious. Now I've done 500-600km things are pretty much obvious there is a clear difference.

So anyhow, if you car is fairly stock and still getting above 13L/100km, and you have tried everything else.. give it a try. Might make a big difference.

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https://www.sau.com.au/forums/topic/80029-i-fixed-my-fuel-economy/
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sl33ek Rising Star

sl33ek

Posted
Posted

Hi there Predator

Isnt it funny how the simple things nearly always work out to be the best solution

Did you use the injector filler on a full/half or near empty tank of fuel?

I'm getting ~350Km out of a tank on my gtst, I hope the injector cleaner will help it out a bit.

MANWHORE Grand Master

MANWHORE

Posted
Posted

I'm going through the same thing atm mate. The only issue I cant think of is this. Once you add the injector cleaner to fuel, it will be very diluted and will have almost no effect. If it was strong, it MAY dissolve the blockage, but will also damage lines and your engine.

It really depends on what the blockage is. If it is sediment or rust, it cannot be dissolved by injector cleaner. I still beleive the best way is to take them out and get them cleaned.

It takes about an hour to take it out with the fuel rail, and then spend $200 to have them cleaned and flow tested.

nedb Proficient

nedb

Posted
Posted

I was using about 14.5 l/100 hile it was fairly stock and now i go through about 16.5 + l/100. I've changed the pump, filter and ultrasonically cleaned the injectors and still no fix.

I'm fairly confident my O2 sensor is working fine.

The A/F ratio is a bit on the rich side but not too bad (11/1).

I have no idea what it could be.

predator Grand Master

predator

Posted
  • Author
Posted

I know I really should pull out the injectors and get them cleaned properly.. this may seem like false economy, but its a bitch of a job, and also to be honest if I am spending $200 for a full injector clean I may as well change the injectors to GTR or other injectors, and spend the money on getting those professionally cleaned rather than dicking around too much with the tiny stock injectors.

nedb: sounds like something weird is going on there, should be nowhere near that high!

Did you use the injector filler on a full/half or near empty tank of fuel?

Basically it said that the bottle was enough for 2 tanks, but it did say you could run it stonger concentration.. so I ran enough for 1 tank in 1/2 a tank (double concentration).. I should fill up another proper 1/2 a tank and use the rest. Don't think there is massive chance of damaging anything? car didn't seem any different to drive. But I don't care too much about my rb20 to be honest.. but I don't want it sucking so much petrol even in mild form.

I'm getting ~350Km out of a tank on my gtst, I hope the injector cleaner will help it out a bit.

Worth trying.. could be any number of things, but for $10 its cheaper than a few other things.

Beer Baron Grand Master

Beer Baron

Posted
Posted
I was using about 14.5 l/100 hile it was fairly stock and now i go through about 16.5 + l/100. I've changed the pump, filter and ultrasonically cleaned the injectors and still no fix.

I'm fairly confident my O2 sensor is working fine.

The A/F ratio is a bit on the rich side but not too bad (11/1).

I have no idea what it could be.

just one question. How do you know your 02 sensor is working properly? have you checked it, or is it just a 'feeling'? if it's the latter get it checked properly using consult or with a PFC hand controller if you have a PFC.

My bet is the O2 sensor.

GTRgeoff Grand Master

GTRgeoff

Posted
Posted

My O2's on the GTR needed to be disconnected to get economy. It was swilling the juice and Bennno told me it eats O2 sensors and had not long had them replaced. Disconnected and sho'nuff it's using at least half the fuel it used to.

nedb Proficient

nedb

Posted
Posted
just one question. How do you know your 02 sensor is working properly? have you checked it, or is it just a 'feeling'? if it's the latter get it checked properly using consult or with a PFC hand controller if you have a PFC.

My bet is the O2 sensor.

I'm pretty sure it's not the O2 sensor coz if you run the ECU dignostics and leave the screw selector in the diagnostics mode and start the car, it puts you into O2 sensor diag mode. Then it flashes on the dash OFF = lean and ON = rich, or was it the other way around.

Mine was changong ON - OFF while I was plying with the throtle and driving around.

dangerous_daveo Grand Master

dangerous_daveo

Posted
Posted
yeah, but cefiros have different ecu's.. tuned for slugging around town no doubt.  

My right foot has a habbit of falling to the floor rapidly during most opportunties - but I can live with that.

Mines a 1990 R32 motor, box, and ECU ;)

I'm also pushing more fuel in to it. Im just saying, thats a bit of a difference still.

MANWHORE Grand Master

MANWHORE

Posted
Posted

Don't worry mate. When the time comes, removing the injectors and fuel rail is not difficult. I had never done it before, and I did not even need to look at the manual. It took about 2 hours to remove (including about 1.5 hours of stuffing around trying to work it out) and 1/2 hour to put them back in.

Sarumatix Veteran

Sarumatix

Posted
Posted

wee this stuff isn't bad and autobarn currently have it at 15 dollars for 2 bottles (meant to be enough for 3 tanks). We just chucked the whole bottle in a full tank, running a lot better now. I'm putting my bottle in tomorrow :).

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