Only one minor problem with the stuck EGR Theory ..
Waterboxer vanagons don't have 'em.

On 2/4/2014 2:21 PM, Robert Stevens wrote:
> 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