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ACCORD EX
08-26-2002, 12:05 PM
today was the first time i tested my gas milage after adjusting the screw ! :D

OLD CONSUMPTION : 1 L > 9 km = 1L > 5 miles
NEW :D : 1L >12 km = 1L >> 8 miles

1L = 1 liter of gas ! :D

MIKE

doug
08-26-2002, 06:25 PM
so you think you went from around 20 miles per gallon to around 32 miles per gallon (US approximates) by tweaking a a/f screw?
strange.

Dutchboy
08-26-2002, 07:32 PM
thats wat i average with mostly city driving and some highway.... on my last long trip..5000km in a few days i got between 42-46mpg....Dont know how but it was great ....less money spent on gas more on beer..
Ben

doug
08-26-2002, 07:47 PM
hey dutch, the best I could do with my '80 & '81 civic wagon 1.5 liter engines was 35 mpg and I was damn happy with that, maybe 40mpg on I-95 to Jacksonville, and here you got a 2.0 liter that you boot around and get 42-46mpg? f'ing unreal. I drive mine agressively and the best I've got is 24mpg, usually it's a even 20mpg, and considering the fun I have, that's OK. These granny stats are starting to trip me big time.

Dutchboy
08-26-2002, 09:13 PM
wel its true..

I drove across canada and it is damn flat and straight.....thats why the mpgs are so high....the tail wind helps alot too....

i could get 500 kms or 312.5miles
to 32litres or 7.1gallons,,,,,,which is 44mpg.....Im as stumped as you are,,,,,
it was 2000kms to were i was heading and i got there on 3 tanks...i could get like 550 miles or mabye more if i dared try to a tank....

THESE readings were remember on flat flat road...well after the first 600km that was..,....
but even today i filled up....35litres and had 450 on the od...and that was mostly in town....
Mabye theres something wrong with my engine...

mystery to me,,
Ben

POS carb
08-27-2002, 01:02 AM
I get 10 MPG in the mustang... take THAT environmentalists! :flash:

ACCORD EX
08-27-2002, 04:11 AM
Originally posted by doug
so you think you went from around 20 miles per gallon to around 32 miles per gallon (US approximates) by tweaking a a/f screw?
strange.

yes man ! this screw is really powerfull i screwed it in for about 3 turns ! and that's hella of a change ! :D

MIKE

ACCORD EX
08-27-2002, 04:11 AM
Originally posted by POS carb
I get 10 MPG in the mustang... take THAT environmentalists! :flash:

hey Eric , do you have a mustang ?? what year !

MIKE

shepherd79
08-27-2002, 04:12 AM
yeah, that is what i got when i messed with it.
it went from 30mpg to about 35-36mpg on highway.
but i am sure it went down after i redrilled the jets.

staticpat
08-27-2002, 07:36 AM
danngit, how do i get to the darneed screw without remving the carb!!!

DanG86LX
08-27-2002, 07:56 AM
I might be wrong but here is my Q: :stupid:
I thought this screw is there for adjusting A/F IDLE mixture. When driving in city or country and those miles add up, there is not much vacuum there ( < 10inHg) sucking fuel from idle passages (not as much as when waiting for the traffic lights ~20inHg). Most of the fuel/air is coming through main jets - venturi. Then where is this huge milage increase coming from ? I bet not from A/F screw.

shepherd79
08-27-2002, 11:20 AM
i don't know how, but somehow it does affect the gas milage and performance.

ACCORD EX
08-27-2002, 12:49 PM
the idle mixture screw is a special screw that pushes some kind of valve to permit air to com into the carb !
so when you screw it in that 's mean more air ! mine was all screwed out which means a lot of gas ! that will cause black smoke and hesitation and may be stalling !

so it's really important !

MIKE

Dutchboy
08-27-2002, 03:10 PM
air fuel will make a hella difference in the performance.....if you run too rich you will be bogging and wasting gas...if you run to lean you can damage the engine after prolonged use and also have the same affects since you now are running not enough to burn well..

the plugs gotta be brown or tan or else somethings wrong with your engine...

doug
08-27-2002, 05:25 PM
something Dan mentioned, and has been totally overlooked, is that the a/f is an idle circuit adjustment that has reduced influence on overall gas consumption outside of idle/near idle situations. at throtle positions beyond idle, richness of the mixture is dependent on other factors.

A20A1
08-27-2002, 05:43 PM
nonono.... the idle jets control how much fuel the idle circuit gets. the idle screw adjust how much of the fuel is used durring idle and up to about 2,500 rpm maybe 3,000.
thats why if you have too small and idle jet you can get hesitiaion, this is because the idle jet is flowing fuel at a slower rate then it is being consumed.
You can also get hesitation if you turn the a/f mixture screw too far in... you'll also nottice that the rpms durring idle will decrease.


well I can understand that stop and go traffic miles are increased with leaning the idle mixture.



shepherd79

i don't know how, but somehow it does affect the gas milage and performance.

yeah thats what tunning the carb is all about... you get 2 ways you can go...
LEAN
- Dry, car doesn't run
- Too lean, bad performance, possible engine damage
- Daily dirver, high gas milage
STOICH - Normal, good mix between performance and gas milage
- Performance, low gas milage
- Too rich, bad performance bad gas milage
- Flooded, car doesn't run
RICH

doug
08-27-2002, 06:45 PM
"how much of the fuel is used durring idle and up to about 2,500 rpm maybe 3,000"

thing is, there are infinite variables when you say up to 2,500, is that cruising at 60mph in 5th gear, or during hard acceleration, or anything inbetween? the accelerator pump dumps more gas than any idle a/f setting unless it's way out. seems like all this great gas mileage is at steady speed on flat surface and not taken over the course of a tankfull of fun agressive stop & go. These guys are reporting granny stuff of cruising at 65mph on a interstate for hours at end and saying "yeah, I get 40mpg." so what? err, I might add i'VE HAD ACOUPLE BREWS TONIGHT.

A20A1
08-27-2002, 07:17 PM
hmm... well if it's all highway driving then it must be all the attentin the carbs been getting... it sort of brought back that good ol' honda efficiency.


I wasn't saying that this was why they got such good miles i was just noting how thigs worked.
The accel pump needs a certain amount a pedal travel to fill back up and to empty it's diaphragm. So the accel pump does effect low off-idle speeds. At cruizing speeds and above you normally hold the pedal down too far for the pump diaphragm to fill up... even if you stomp the gas the diapragm wont have much power to push what gas it has thru the carb.

doug
08-27-2002, 07:26 PM
"At cruizing speeds and above you normally hold the pedal down too far for the pump diaphragm to fill up... even if you stomp the gas the diapragm wont have much power to push what gas it has thru the carb."

that's why you blip the throttle, and if it's a solid diaphragm it will be a solid squirt through the pump shafts' total spectrum of delivery.