Bad Fuel Consumption!!!

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jangz
Posts: 269
Joined: Wed Jan 06, 2010 2:52 pm

Bad Fuel Consumption!!!

Post by jangz »

Hey everyone

I'm starting to have big concerns with the ever increasing fuel prices and my Civic's MPG.

I fill up 30 litres and get only between 190-160 miles before I have to fill up again!!! That's like 28-22ish MPG. OK now and again I foot it but 90% I'm casual, drive to work at back and to the local supermarket and that's pretty much it. My drive to work is approx 8 miles there and 8 miles back.

Is there something wrong with my car?

I had my z6 intake manifold and vtec head fitted (ignition timing I don't think is good because it stutters around 1k to 2.5k RPM. I'm also using the z6 fuel injectors.

Can all these mods be why my car is so bad with fuel?

What are your average city MPG?

I think bigger engine cars are doing much better than me with regards to fuel consumption.

Any suggestions??? >_<
Liberate our minds by any means necessary - Malcom X

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BETEK
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Joined: Wed Oct 21, 2009 10:09 am

Re: Bad Fuel Consumption!!!

Post by BETEK »

Maybe the problem is the timing.
But also check fuel filter, air filter, injectors and the spark plugs.

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jangz
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Joined: Wed Jan 06, 2010 2:52 pm

Re: Bad Fuel Consumption!!!

Post by jangz »

Yeah I will be doing a service to it soon. I think I started noticing how bad it was since the Vtec conversion as it was done very ghetto style with no strobe to time the ignition.

Again I wanted to also find out what is normal or the realistic MPG within the city driving for our 1.4i Civic and not what it says on the manufacture details.
Liberate our minds by any means necessary - Malcom X

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Dodo Bizar
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Joined: Mon Jun 22, 2009 10:36 pm

Re: Bad Fuel Consumption!!!

Post by Dodo Bizar »

I get 14 km out of a liter with my D14A3 on a bad day with only short pieces. Distances shorter than 20 km and a lot of traffic jams each day.

On a good day it gets 1:15.5, summer, long distance. Before the IM swap to Skunk2 etc. I even got to 1:16 in the summer. Litre:km I talk about.

So on 30 litres I typically get 420 - 460 km or 260 - 290 miles.

Now either timing is way of (killing your engine slowly in the process if its too advanced!), lambda is not working properly (affects only during light load) or the camshaft is not placed with the right timing. But the last one means its really way of, since generally you can put it wrong quite badly before really noticing anything.

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Dodo Bizar
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Joined: Mon Jun 22, 2009 10:36 pm

Re: Bad Fuel Consumption!!!

Post by Dodo Bizar »

Ow and rims? Sometimes people completely overlook they have big ass heavy 17 inch and tupperware on the bumpers... those things don;t help either. I drive with 15 inch 195/50R15 tires.

Firebass
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Joined: Wed May 26, 2010 8:35 pm
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Re: Bad Fuel Consumption!!!

Post by Firebass »

i had bad fuel consumption also when i changed m y old oxygen sensor on the headers it went back to normal
Up the Rev Limiter !!!!!!

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saxophonias
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Re: Bad Fuel Consumption!!!

Post by saxophonias »

i had very bad mileage with my 309 pug (10lt/100) being only 1.4 8v. The advance was way off. I Changed the dizzy and it improved a bit. I guess it has to do with the bigger injectors in combination with bad fuel maps maybe.
During the winter (lot;'s of cold start ups) and not very economical minded driving the consumption ranges from 6.5 to 7.5
When on open road and up to 120km/h it consumes significantly less, aprx 5 lt.

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jangz
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Joined: Wed Jan 06, 2010 2:52 pm

Re: Bad Fuel Consumption!!!

Post by jangz »

I done a bit of reading to try and find out what could be the issue causing this.

I agree Saxo that yes it may be a combination of bigger fuel injectors and having a bad map and/or being un-tuned, but before I got the head swapped fuel consumption was never an issue and still had the same injectors, IM and ECU.

I'm thinking its a lot to do with the timing being way off. I am not actually sure what the timing is at the moment but I will be getting a timing light soon so I will look into it soon.

What timing should I be looking to set it to at the ignition for best power and what should i be looking to adjust at the adjustable cam gear for my Vtec head to make the most out of the swap???

I really, really appreciate everyone throwing their experience, advise and suggestions. If there are any other thoughts please continue to add to it, I'm sure it will help me and others in future should someone face this again.
Liberate our minds by any means necessary - Malcom X

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saxophonias
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Re: Bad Fuel Consumption!!!

Post by saxophonias »

you might want to take a look at Joris writings about the vtec head. I think he mentions something there about how it should be timed. As for the best timing for your set up i am afraid it must be done on a dyno so as to see exactly what it does.

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jangz
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Re: Bad Fuel Consumption!!!

Post by jangz »

Yeah, I have read it a lot of times but I got confused as to shall I set it to the standard 16 degree ignition (as its more of a standard setup cam etc) or 18 degrees as I read later on in the article?

Joris stated on the first run it was 122bhp as it was set to standard D16z6 timing but later changed it up. Was that changing the ignition side or the cam gear, I presume it was the cam gear?

I was thinking as its nearest to standard setup stick to 16 degree on the ignition and when it comes to turbo then mess about with the adjustable cam gear to squeeze some power out of it, would that be sensible?
Liberate our minds by any means necessary - Malcom X

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