On Feb 4, 2014, at 3:05 PM, TJ Hemrick <x53gunner@GMAIL.COM> wrote:

87 Vanagon GL, 2.1, Auto.  Water pump gave up the ghost-fixed that,
starter issues-finally got a good one, now the beastie won't idle to save
it's life.  If I disconnect Temp 2 it idles at 1800 rpm (smooth as silk) no
matter what else (even the air screw in the throttle body completely
closed).  New Temp 2 sensor-no change.  O2 sensor, no change connected or
not.  Starts smooth but within minutes, runs really rough, misfires,
running *super* rich (black smoke).  Any thoughts or suggestions?

TJ,
Whether this has anything at all to do with your motor/situation or not?????

My Subie 3.0 H6 had exactly the same symptoms. Turned out to be the EGR.

It does not work/open until you accelerate, then the valve opens and recirculates
exhaust into the intake. When the valve stops working (mine was blocked open
with a small piece of carbon, and eventually burned a cract/crease in the valve
seat, and would not work) properly, it stays open at idle, which makes the idle
engine speed up and run rich.

The easy diagnostic is to start the engine and immediately touch the EGR.
If it's warm right away, that means exhaust is pouring through it, which it should
not at start-up-idle. It should only get warm if you immediately accelerate, which
opens it's valve normally.

Bob