Defective T stat?  I had this problem once, and it turned out the T stat
(OEM) used a rubber O ring on the valve which had partially detached and
jammed the valve open about 1/8th inch.   You can get a cheap IR temp reader
from HF and do some checks around the T stat area.

Stuart

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Craig Cowan
Sent: Thursday, January 24, 2013 9:27 AM
To: vanagon@GERRY.VANAGON.COM
Subject: TERRIBLE GAS MILEAGE/Running Cold?

Hello Gang!
My '90 GL (Automatic) is giving me troubles. Some may recall this van had
sat for a few years before I came to own it, and I have turned it around to
a reliable  daily driver. Anyway.... It's time to throw more work into it.

I had previously had a problem with the temp gauge never rising above 1/3 on
the gauge and it wouldn't make good heat. Of course I had a bad dash blower,
so wasn't all that sure on the heat.
Gas mileage was always bad. 14mpg max.
Well last weekend I finally replaced the thermostat and things were looking
good! The temp gauge would now read right in the middle, and with the new
dash blower as well, i now had heat!
But surprisingly, the gas mileage suffered still.
Yesterday I filled up and found I had gotten 10.5mpg on that tank.

Today I did some highway driving. This bus runs like a champ! Seriously good
power, however I now see that the temp gauge will drop all the way to the
bottom if I cruise at anything above 60mph. Anything below 50mph will
maintain the temp gauge right in the middle, where it should be.
I've never seen this happen. Any ideas?

I believe this weird temperature problem could account in part for my
terrible gas mileage. I recognize that I shouldn't quite be expecting 20mpg,
but 17 would be a reasonable thing to find from an auto bus in my
experience. There are a few even in my area that do get 20mpg, easily.

Any thoughts?

-Craig
'90GL
'87 SUNROOF SYNCRO WESTY ZETEC
'85 Barn