Help!

I am an old-style air-cooled-head person, but I have been recently
given an '89 or '90 vanagon for a couple of months while its owner
is overseas. I am to take care of it and put labor into it for
the exchange of driving it for free.

It is having idle problems. Symptoms:

	High coolant temp. Not off the scale, but at the top 75%
	Idles rough, like misses on one cylinder, but not regular.
	The rough idle is noticible after it warms up, but it does
not want to go when cold either.
	When I start it when it is cold, it usually idles well, until
I put it in Drive. Then it usually gets real rough, goes to 3-400 RPM,
and threatens to stall. Stalls sometimes when I try pulling away.
	Mostly it wont go into fast idle when cold, but trys to idle
at 400 RPM. 

Things I have already tried:
	New fuel filter. (needed it any way)
	New Oil.
	New Transmission fluid and filter. (neededboth)
	The computer says everything is AOK.
	Injectors have been cleaned with STP additive.
	Timed up. (Checked all the plugs and wires, OK)

Not having experience with a vehicle with more than 3 wires and two
feet of vacuum hose, this engine befuddles me. What should I check next?
I have the Bently, but its dignostics say to go into dismantling
the fuel system, checking pressures, pulling the computer, etc.
I dont have bucks to try the 'swap-and-pray' scheme of repair. I know
my way around a multi-meter, but dont know what to test.

What should I check? What are some common failure points with the
fuel injection system?

--- Chris Chubb (cchubb@ida.org)
__________________________________________________________________________
\All opinions expressed or implied may not reflect those of the Institute \
 \for Defense Analyses, the US Government, or anyone else.                 \
  --------------------------------------------------------------------------