Bad Fuel Economy

[pocvw]

I have recently tested the in-town gas mileage of my three vehicles:

2002 VW Passat v6 - 15 mpg
1995 Toyota Corolla - 19 mpg
1980 VW Westy - 8 mpg (and she only has 1200 miles on a rebuilt motor)

All three vehicles should be doing better than that (especially the westy!!). Is this a case of bad gas or do my vehicles need help (question is really for my westy, but I thought i'd throw in the other two vehicles because they are doing poorly on gas as well - thought it might be some bad fuel). Tell me what you think!!! Thanks!!

pocvw
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Life is a garden - dig it!

1980 VW Westfalia

[Miguel Arroyo]

Lets ask about some obvious things:
-Are your tires at optimun pressure?
-Are your brakes dragging?
-Are you at a high elevation or at sea level?
-When was the last time you replaced the air filter?
-Is the choke on at all times?
-How is the timing?
-Valves adjusted correctly?
-When was the last time you did a tune up?
-How heavy an oil weigth are you using?
-Is your clutch slipping?

Good luck.

[Randy in Maine]

Also:

Is your gas heater on all the time?
vacuum leaks?
Tires stock size or close?
Thermostat correct?
Change out your Temp Sensor II?
Have you "zerod out" your hydraulic lifters yet?
Fuel leaks?
Injector spray pattern?

Cold weather is tough on all cars when it comes to mileage.

[pocvw]

Thank you Randy,

I will need some time to look into all of those issues, but I sure appreciate the great info!! Thank you!

pocvw
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Life is a garden - dig it!

1980 VW Westfalia

[Randy in Maine]

Start by just doing a basic tune up. Points/condensor/plugs and if you notice the plugs have been ruuning rich, have a good look at the temp Sensor II over by #3 cylinder. Really easy for it to not make a good mechanical or electrical connection.

Sometimes you can test them out of the car and they will be "OK" but they don't wat to work right when in the car. I keep a new sensor in my tool box just in case. A likely tale of woe and intrigue.

Read your Bentely on how to check that aux air valve to make sure it is closing correctly when it warms up. Having a working thermostat halps as does the correct fuel pressure. If you click on my "gallery" here, there is a picture of my Home Depot fuel pressure gauge that you can make for $10 at the Depot. Good enough for what we to do.

Timing/vacuum leak inspection/idle speed set and zeroing out those lifters can all be done in a sunny afternoon unless you live in Maine where it is snowing again today.

Don't be afraid to hook up your timing light the see if the dizzy is advancing nice and smoothly both up and retarding down the RPM scale. They also need a little cleaning and lubricration one in a while. A drop of oil on the little pad at the shaft helps and I use a very small amount of white lithium grease at the pivot point in there also. Thank god every day you don't have a 009 distributor on there!

You should have this thing up close to 20 mpg in no time. It is a big car with a small engine that has to work hard to get it moving and cruising RPM is around 3600 or so.

[uncle chuck]

GUYS, THE ABOVE TIPS ARE ALL GOOD!! DO THE BASICS FIRST....

THEN GO TO WATER INJECTION. THE EUROPEANS HAVE BEEN DOING IT FOR YEARS WITH THEIR $7.00 PER GALLON PETROL.

I KNOW THAT THERE ARE A LOT OF SKEPTICS OUT THERE, BUT OUR COUSINS OVER SEAS WOULDN'T BE USING WATER INJECTION IF IT DIDN'T WORK, WOULD THEY??? RIGHT...

I FIRST ADDED A RUDIMENTARY WATER SYSTEM TO MY 71 WESTY, SHE WAS ONLY GETTING 18 MPG, AND I WAS CHEAP. I HAD ALSO HEARD THAT SOME OF THE WARPLANES IN WW2 USED WATER INJECTION IN THE ATTACK MODE TO INCREASE THEIR RANGE AND CEILING.

SO... I THOT, AIR COOLED ALUMINIUM AIRCRAFT ENGINE AND WATER INJECTION WORKED OUT OK... HOW ABOUT AN ALUMINIUM AIRCOOLED BUS ENGINE ???

LONG STORY SHORT PLUMBED WATER INTO THE VAC. ADVANCE PORT ( THE AIR THERE IS MOVING AT THE SPEED OF SOUND.) AND LET THE VACUUM AND AIRSPEED TURN IT INTO VAPOR.

THE BUS ON IT'S MAIDEN VOYAGE OF 99 MILES MADE THE TRIP ON 1.5 GALLONS OF GAS AND A QUART OF WATER.. THATS 66MPG AT 73 MPH. AND WE THINK THAT THE EUROPEANS ARE ON TO SOMETHING??

FOR MORE DATA THAN YOU CAN STAND CHECK OUT WWW.EAGLE-RESEARCH.COM...PS THIS SETUP ALSO MAKES 10 TO 20% MORE HP (AT THE ENGINE BUILDERS CONTEST IN HOT ROD MAGAZINE THEY WON'T LET THEM RUN WATER INJECTION .. WONDER WHY.. MORE LATER UNCLE CHUCK

[uncle chuck]

GUYS (AND GALS TOO) A SHORT P.S. TO MY WATER INJECTION NOTES... THIS WORKS VERY WELL ON CARS W/O OXY SENSORS. ON CARS WITH OXY SENSORS IT GETS A LOT MORE COMPLICATED...

ON O2 SENSOR EQUIPPED CARS THE O2 SENSOR "TALKS' TO THE COMPUTER THE COMPUTER WANTS TO SEE A 500 MILLIVOLT SIGNAL TO KNOW THAT ALL IS WELL.

IF YOU ADD WATER TO THE COMBUSTION MIX THE O2 SENSOR WILL SEE THE EXTRA O2 FROM THE WATER AND DROP VOLTAGE TO APX 300MV CAUSING THE COMPUTER TO RICHEN THINGS UP SO THAT IT GETS BACK TO 500 MV. IN SHORT YOUR MILEAGE WON'T IMPROVE, BUT YOU CAN RUN REALLY STRONG!!

THE NEXT THING YOU HAVE TO DO IS CONVINCE THE COMPUTER THAT ALL IS OK. THIS CAN BE DONE... CHECK OUT EAGLE- RESEARCH.COM I WOULD LIST ADDITIONAL SOURCES IF I HAD THEM BUT AT THIS TIME I DON'T. I'M JUST WORKING ON A 50 MPG V8 CHEROKEE ( 50 MPG SOON I HOPE) UNCLE CHUCK

[nathan@el]

[Crughy]

Hum... first post... all in upper case...

And on top of all: a dumb scam...

I guess when you have no class, you really have no class...

JP

[tencentlife]

Let's approach this scientifically. What things do all three cars have in common?

Climate? Assumedly so.

Fuel source? Ditto.

Driver?

Hmmm.
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Experience is kryptonite to doctrine.

[reluctantartist]

Look at this article ...

http://www.motherearthnews.com/Green-Homes/1979-09-01/Water-Injection-Wizardry.aspx

that may be a scam but there may but there are other articles related to water injection....have to wonder if for the air cooled motor it is possible just for keeping the temperature down.

But back to the post...I am in the process of replacing all my vaccum lines and testing for leaks.I am going to do the test described in the bosch fuel injection manual using a compressor at 4psi to see what leaks there are...hopefully will have none by time i am done. I have a cali injection so luckily the westy ran with the leaks but my milage was around 15 mpg. I think it can do better.
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.

[Crughy]

A 73 bus with 66mpg...

Must have been smoking pretty good (not the bus...)


JP

[Wildthings]

Water lowers the charge temperature just the way exhaust gas recirculation does. You don't see many people wanting to add exhaust gas recirculation to their engines do you? Though if it will allow you to run higher compression you will likely see some gains or maybe you could run some extra timing advance which would also give gains.

This is old technology which does have some benefits, but it probably also has serious negatives. The engines in the WWII fighter aircraft only had to survive for a few hours or days while I want my VW engines to survive for decades.

[reluctantartist]

I did some quick research on it and it looks like if you take a stock engine and do this you can slightly advance the timing to take advantage of it for a torque increase.....but you need to monitor the water level...wouldn't want to run out. I want my engine to run forever too....I originally got over 165k on it before the cooling fan bolts sheared and it over heated
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1982 Westy, 1974 412 Variant... Yes, Aircooled's are great! Oh and I do have modern computer controlled vehicles too, but I just don't care about them.

[BrownBertha]

I would guess the 02 sensor. the only time i got that bad of gas milage the 0 2 sensor went bad.

[devesvws]

Why is it every time someone comes up with a gas saving idea its a scam? The biggist scam of all is the auto makers in bed with the oil industry. It's a proven fact, and sad at that, yet no one cares until gas prices go's through the roof. And yet people are still driving like a bat out of hell, 10-25 miles over the posted speed limit is very common here in VA. In most of my driving years my speeds have been within the law most of the time. The fact is, I very rarely speed in order to do my part saving energy. The acetone trick... is it fact or fiction? My last fill up in my 87 Vanagon was 20 mpg, and lately is been like 17-19. I am willing to try any thing affordable, 1 1/2 ozs of acetone costs very little, slowing down costs nothing, shutting off your motor at long red lights helps too, and installing a better vw motor set up to get a few more mpg costs a fortune. the other things like a new oxygen sensor, cleaning your plugs periodically, 10w30 oil in non oil using motors all helps.

[bmwloco]

Good guess, the 02 sensor.

You've obviously owned a water boxer for a while if you know that

My '85 Vanagon Westy gets 19mpg city. Highway is 21-22 on the flats.
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'85 Vanagon Westfalia