Dylan:

You didn't say WHERE in Colorado you '81 won't start.  If you are
above about 9000 feet, you may be having just normal behavior.
If you are in the front range, then what I'm saying doesn't apply
(to my VWs), but from what you say, you are still flooding.

I drove my '76 and my '81 all over the mtns in winter, skiing, etc.
After many failures to start and begging pushes or tows from big
SUVs, and messing with the cold start valve, I finally figured
out that it is just a little too rich and you have one chance to
get it started---crank with the pedal to the floor for max air
and to rev it up if it catches. If it doesn't start the first
time, you are flooded.

I don't know how many times I chugged 100 yards on the starter
to get to the downhill slope after skiing at Brainard Lake.
I bet I have 2-3 miles total on my starter! ;-)

I put a switch in the wire to the fuel pump.  The switch is under
the drivers seat.  I just turn off the pump, keep cranking and
when it catches, turn the pump back on. I have always been able
to start with this switch.

With over 200,000 miles of this stuff in these two vans, I am
convinced there is a design flow in the injection system.
I suspect they didn't test at 10 degrees F and 10,000' elevation!

If I can help, call me at 303-601-0451 (cell).

                        Richard A. Jones
                        Boulder, Colorado
                        '81 Vanagon   Mr Bus
                        '87 Syncro Westy   El Jefe