Date: Wed, 2 May 2012 18:03:51 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Still lousy gas mileage
In-Reply-To: <BLU162-ds197FB470596DF4429F04F8CE2E0@phx.gbl>
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See below!
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Bryan Feddish
Sent: Wednesday, May 02, 2012 5:18 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Still lousy gas mileage
If you ever drove with me you'd see how I get 20-22 MPG. hahhahhah Nobody
wants to be behind me....
Anyway, timing is advanced 5-10 degrees, it always seems to like that spot.
While over advancing the timing make it idle better, seem more responsive at
low to mid speeds and make you think it is running better, it can actually
be bad especially during extended high speed/load operation. To begin with
if you fire too early the explosion will actually fight the piston on its
way up on the compression stroke resulting in a net loss of power. This will
also increase piston heating and possibly bring on pre-ignition-pinging.
The water boxer does a great job of not letting you hear the pinging until
just before the pistons start to melt. Set it where it belongs.
The Boston Engine only has 15K miles on it but I will do that cylynder
balance test this weekend if I do not get a chance this week.
New or rebuilt engines do sometimes have things go wrong. Even if I repair
them! Compression-leak down should have been done after install and after a
few thousand miles to get a baseline and make sure all is good.
Tires have 8K on them, all wheels aligned.
What tires?
How do I "test" a catalytic converter?
Vacuum gauge on intake manifold. Pressure in exhaust. Remove and inspect.
Get a full size cat like the Emico.
Thanks,
Bryan
Dennis
-----Original Message-----
From: Dennis Haynes
Sent: Wednesday, May 02, 2012 5:05 PM
To: 'B Feddish' ; vanagon@GERRY.VANAGON.COM
Subject: RE: Still lousy gas mileage
Considering today's "clean" low BTU fuels and your vehicle 22 mpg is a
stretch. Especially if you drive at higher speeds or facing headwinds. 17 is
a bit low but there are many factors that can influence fuel economy
especially on older engines. How much do want to invest on diagnostic to
gain 5%?
Engine compression-leak-down! Is everything being put into the engine
burning and making power?
Ignition timing?
Use the O2 sensor to test mixture control.
Cylinder balance. Disconnect injectors with engine running one by one. Do
all cylinder cause the engine to drop the same RPM when disconnected?
After that check exhaust-catalytic converter.
Choice of tires and wheel alignment.
After all that you pretty much have what you have.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of B
Feddish
Sent: Wednesday, May 02, 2012 1:01 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Still lousy gas mileage
So on my trip north this past weekend I only got 17 mpg on the highway with
my 83.5 w/c Westy. That is my normal city mileage. I should have gotten at
least 20 if not 21-22. All the usual suspects have been checked. if anyone
has any last minute suggestions for me that I can try this weekend let me
know. Otherwise it looks as though I will have to take it the expensive
mechanic who I know is going to charge at least a few hours and still may
not find something.
Thanks,
Bryan
