Fuel Economy 101 - The Acura Legend & Acura RL Forum
Acura Legend Forum Acura Legend Forum
 

» Auto Insurance

» Featured Product
» Wheel & Tire Center

Go Back   The Acura Legend & Acura RL Forum > Shop Talk > DIYs

DIYs These threads contain answers to common topics. "Do it yourself" modifications are also archived here.

Acura-Legend.com is the premier Acura Legend Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Rate Thread Display Modes
Old 12-24-03, 04:32 AM   #1 (permalink)
Registered User
 
Join Date: Sep 2003
Location: Canada
Posts: 421


Car 1: 1992 Granada Black LS Sedan


iTrader Score: 1 reviews
Fuel Economy 101

Many members have written about bad fuel economy and I am one of them I would like to target this issue and resolve it once and for all. I have gathered bits and pieces from other posts and the net to compose this thread. I would like to attempt to compile a check list with the help of all of you that everyone can contribute to, and use to help resolve each of our particular fuel economy related issues. I am looking forward to participation from everyone who has some insight. Also, maybe we can all post our gas mileage to compare.
Thank You

Introduction:

The fuel system provides fuel storage in the vehicle, filters out particulates, delivers fuel to the intake air system, and mixes the air and gasoline in the correct ratio to provide the most efficient combustion (i.e., the highest fuel efficiency) in the engine.

Making sure your flow of gas is not blocked is vital to getting the most mileage for your money. Optimal use of your gasoline is helped by fighting the accumulation of performance robbing deposits in the fuel system. Today's modern engines are more susceptible to deposit build-up than ever before. Deposits have been found to start forming in as few as 1,500 miles. Studies have shown that deposits can decrease your fuel efficiency by as much as 11 percent.

The list:

1. One main factor for decreasing fuel economy is a partially blocked exhaust . As catalytic converter undergoes wear and tear, they may collapse internally, leading to restricted exhaust from the engines.

2. Dirty air filters can also cause your engine to run at less than peak efficiency.

3. Malfunctioning brakes can significantly increase fuel consumption because the vehicle must work harder to overcome the resistance.

4. Check for misaligned tires , which will drag instead of rolling freely, leading to increased fuel consumption and causing problems with the car's handling.

5. New spark plugs alone can increase fuel economy by 3%.

6. The Positive Crankcase Ventilation or PCV valve regulates the flow of unburned gases from the crankcase back into the combustion chamber, to be re-burned. The valve helps maintain correct fuel economy and idling, and prevents oil and gases from accumulating in the air filter housing.

7. Fuel injectors are manufactured to operate and last for 150,000-plus miles. Because of their significance on emissions, some vehicle manufacturers warranty injectors for five years or 50,000 miles. However, over a period of time, harmful deposits can build up around an injector nozzle. Deposits can also build up inside the injector or clog the injector filter basket and reduce the amount of fuel being delivered. When the fuel delivery decreases, the injector pulse width will increase, creating additional heat in the injector. A leading cause of this is short-drive cycles. Short-drive cycles with repeated temperature change create fuel diffusion. The lighter gases evaporate and the heavier particles of the fuel settle at the tip of the injector. Engine heat then bakes the heavier particles, making them hard deposits. The deposits can clog an injector, reducing the volume of fuel delivered or distort the spray pattern. When the fuel delivery is out of spec, driveability problems exist because the powertrain control module (PCM) is unable to maintain the proper overall air/fuel ratio. Some injectors may be commanded by the PCM to go richer or leaner depending on if the problem injectors are clogged or leaking.

8. The thermostat plays an important part in obtaining good fuel economy. Temperature sensors on the engine tell the fuel injection computer to inject more fuel when the engine is cold. A faulty thermostat will prevent the engine from reaching normal operating temperature so extra fuel is always being injected. If the temperature gauge is reading low or the car heater is not putting out hot air, have the thermostat checked immediately. Your fuel economy will increase.

9. Change Your Fuel Filter . Your fuel filter removes contaminants including rust and corrosion from the fuel before it enters the fuel injectors or carburetor.

10. Oxygen sensors "may" need to be replaced. The codes are 41 and 42.You can check your Oxygen sensors with a (DVOM) Digital Volt Ohm Meter.
Common symptoms of a worn out sensor include excessive fuel consumption, high emissions, engine surging or hesitation, or premature failure of the catalytic converter. When examining the sensor, a shiny deposit on the sensor's heat shield or any gummy deposits indicate it's time to replace the sensor and determine the root cause of those deposits.

Inoperative or faulty sensor signals can result in the ECU causing engine backfire (due to a rich mixture), rough idle quality and lean condition misfire. Also, bear in mind that a “faulty” oxygen sensor data signal may actually be caused by malfunctioning component(s) of other systems such as the EGR (Exhaust Gas Recirculation) system. Also included are plugged fuel filters, vacuum leaks, inadequate (too high or too low) fuel pressure, fuel injectors leaking gas or air, leakage on the exhaust system or other related parts. Do not automatically assume that the oxygen sensor itself is the root cause of the sensor code. Remember also, a degraded oxygen sensor does not always set a code. If the sensor is replaced, a future sensor code or engine damage may be triggered again if the root cause is not corrected.

11. Exhaust Gas Recirculating (EGR) system .
Here is a good link: http://www.autoshop101.com/forms/h61.pdf

12. Throttle Body inspection and cleaning.

http://www.southgatemotors.com/item_1.htm

http://www.mm-inet.com/535594.shtml

Some of the members have recommended getting some
BG 44K Fuel System Cleaner.

http://www.bgprod.com/bgprofessional.../autofuel.html

http://shop.store.yahoo.com/wyattarp...bgautprod.html

I already bought some Liqui Moly Jectron, Liqui Moly Ventil Sauber and Liqui Moly Pro-Line Fuel System Cleaner, because it is available locally and the BG44k is not.
If the Liqui Moly doesn't work, then I will try the BG 44K.

The liqui-moly site is :
http://www.liquimoly.de/web/lmhomeen...es/index_flash

Last edited by Mike Diaz; 12-27-03 at 06:41 AM.
Danny is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 12-24-03, 04:53 AM   #2 (permalink)
Registered User
 
Join Date: Jan 2002
Location: Irvine, CA
Posts: 1,658


Car 1: 1994 GS Black / Tan


iTrader Score: 0 reviews
Send a message via Yahoo to ILOVELEGEND
Good pointers Danny. Thanks for putting it all together. I've saved it all on my computer.
ILOVELEGEND is offline   Reply With Quote
Old 12-24-03, 04:55 AM   #3 (permalink)
Banned
 
Join Date: Nov 2003
Location: Florida
Posts: 383


Car 1: 94 Legend Coupe


iTrader Score: 1 reviews
Awsome post. Thanks for doing great research. You might want to add driver on the list b/c some of us just tend to push the throttle a little further than others. lol j/p
94LegendCoupe is offline   Reply With Quote
Old 12-24-03, 05:06 AM   #4 (permalink)
Registered User
 
Join Date: Jan 2002
Location: Calgary, AB, Canada
Posts: 3,199


Car 1: 1993 LS Coupe, 6 Speed


iTrader Score: 0 reviews
Great Information.

A Mod should move this over to the DIY Archive.

Nice Work.
Mckenzie93 is offline   Reply With Quote
Old 12-27-03, 01:12 AM   #5 (permalink)
Registered User
 
Join Date: Sep 2003
Location: Canada
Posts: 421


Car 1: 1992 Granada Black LS Sedan


iTrader Score: 1 reviews
Can we see some of your fuel consumption numbers please.
Let's do a comparison.

I get a maximum of 375km per tank also (city driving).
This last month the temperature has dropped and so has the mileage to about 325km.
I was getting about 425km - 440km about 6 months ago.

Use this site for conversion:

http://www.escapeartist.com/Miles_Ki...Converter.html
Danny is offline   Reply With Quote
Old 12-27-03, 05:00 AM   #6 (permalink)
Registered User
 
shahavchik's Avatar
 
Join Date: Jan 2002
Location: Seattle, WA
Posts: 972


Car 1: 1994 Granada Black Acura Legend GS Sedan
Car 2: 2007 Subaru Forester


iTrader Score: 0 reviews
Send a message via MSN to shahavchik
Quote:
Originally posted by Danny
Can we see some of your fuel consumption numbers please.
My Numbers
shahavchik is offline   Reply With Quote
Old 12-27-03, 05:24 AM   #7 (permalink)
4ever & ever & ever ever
 
Join Date: Jan 2003
Location: el paso, texas
Posts: 1,208


Car 1: 1991 Frost White Legend Sedan L


iTrader Score: 0 reviews
Send a message via AIM to Legend4ever
Thanks for the info.
__________________
"F*** popo, we blowin dro out the ack legend"
Infinity945@aol.com
http://www.photohost.org/gallery/dat...4ever_Sig2.jpg
Sig By KnO12TrUsT



My Car is for sale, check in legends for sale section........
Legend4ever is offline   Reply With Quote
Old 12-27-03, 06:40 AM   #8 (permalink)
Registered User
 
Join Date: Jan 2002
Location: N Canton, Ohio
Posts: 9,173


Car 1: 3.5L 1991 LS Coupe 5 Spd Blk/Blk
Car 2: 1999 Acura 3.5RL
Car 3: 2004 GMC Sierra Z71


iTrader Score: 5 reviews
Send a message via AIM to Mike Diaz
Quote:
Originally posted by Mckenzie93
Great Information.

A Mod should move this over to the DIY Archive.

Nice Work.
Done
Mike Diaz is offline   Reply With Quote
Old 12-27-03, 06:56 AM   #9 (permalink)
B**keye Member
 
Join Date: Nov 2002
Location: BAMA
Posts: 1,118


Car 1: 1988 Acura Legend L Sedan 5 speed 95k miles


iTrader Score: 0 reviews
Send a message via AIM to Dan88Legend
hey i blocked my whole EGR system... how much MPG would i expect to lose?
__________________
http://dansacura.20m.com/engine1.JPG
http://www.dansacura.20m.com/lowered.html
This legend is dead.

My new toy:
'99 Pearl White Toyota Solara
5 speed V6
K&N drop in filter
I want: TRD supercharger & Short shifter
Dan88Legend is offline   Reply With Quote
Old 12-27-03, 07:01 AM   #10 (permalink)
Registered User
 
Join Date: Jan 2002
Location: N Canton, Ohio
Posts: 9,173


Car 1: 3.5L 1991 LS Coupe 5 Spd Blk/Blk
Car 2: 1999 Acura 3.5RL
Car 3: 2004 GMC Sierra Z71


iTrader Score: 5 reviews
Send a message via AIM to Mike Diaz
A lot, why block it?
Mike Diaz is offline   Reply With Quote
Old 12-28-03, 12:49 PM   #11 (permalink)
B**keye Member
 
Join Date: Nov 2002
Location: BAMA
Posts: 1,118


Car 1: 1988 Acura Legend L Sedan 5 speed 95k miles


iTrader Score: 0 reviews
Send a message via AIM to Dan88Legend
i didnt notice a change in my MPG. well its a long story but i broke the EGR pipe when putting on my intake manifold so i said what the hell and just blocked it off. car runs great
__________________
http://dansacura.20m.com/engine1.JPG
http://www.dansacura.20m.com/lowered.html
This legend is dead.

My new toy:
'99 Pearl White Toyota Solara
5 speed V6
K&N drop in filter
I want: TRD supercharger & Short shifter
Dan88Legend is offline   Reply With Quote
Old 01-05-04, 06:52 PM   #12 (permalink)
*he S*per A**ra*or
 
Join Date: May 2003
Location: Stuttgart/Germany
Posts: 197


Car 1: black 93 EDM KA7 M/T


iTrader Score: 0 reviews
Blocking the EGR valve is a good option to give you a small bit of more power and a longer life to your spark plugs and keeps the intake manifold clean. But inline with blocking/removing the EGR you should punch or remove your catalytic converter, because it will get too much dirty exhaust gases and will be soon without function (stuck with deposits), so just punch the ceramic mesh out of it or replace it with a straight pipe. Removing cat converter and EGR is a highly recommended mod on tuning turbo engines. I did it on my 300ZX and had great efforts. The higher the engine power (and air consumption) the higher is the power raise that will result.
__________________
<center><a href="http://www.honda-legend.com">www.honda-legend.com</a>
<img src="http://www.honda-legend.com/STUFF/smileys/oo-oo.gif">
<img src="http://www.honda-legend.com/STUFF/signature_2005.jpg">
<br><b>Still willing to move to USA!</b>
I'm highly motivated, multi-skilled, very creative and reliable and searching for opportunity to work in the USA.<br>If you can help to make a straight Legend-drivers dream come true, email to admin@honda-legend.com</center>
KevinKA7 is offline   Reply With Quote
Old 01-23-04, 06:03 AM   #13 (permalink)
Registered User
 
Join Date: May 2003
Location: Tampa
Posts: 42


Car 1: 1993 Green 4dr LS


iTrader Score: 0 reviews
Send a message via AIM to specialk79
The BG 44K Fuel system cleaner is available on Ebay for $19.95 Shipped!!
specialk79 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

  The Acura Legend & Acura RL Forum > Shop Talk > DIYs


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -4. The time now is 03:52 AM.



Powered by vBulletin®. Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
© AutoGuide