Have you tried adjusting the valves and setting the timing?  I don't see
that in your list of fixes, and if the PO didn't do it right after fixing
the heads it could be causing some trouble, though I have no idea if that
would cause the symptoms you describe.

Fred Younger
91 GL

> From: William Dummitt <williamd@COMPUSERVE.COM>

> For a couple of months now, I have been trying to troubleshoot an 87 syncro
> that persists in running rich.  It always starts right up, but will die if
> left idling as the mixture gets richer.   It can be driven (sort of) but
> usually dies at stop lights (always restarts) and has little power-hard to
> get above 50 mph or so.  I've spent many hours on it, so has my local
> independent vw mechanic (he's not bad, but doesn't see many late-model
> vanagons).  I have a good-running 87 van to swap parts from, but I STILL
> can't diagnose this problem.  When I bought it it wasn't running
> particularly well, but I was confident that I could fix it.  At the time it
> had the cat converter replaced with a straight pipe, no oxygen sensor.  It
> also had a bad afm.  I installed a converter and oxygen sensor and a good
> afm ( works fine if I swap it into another van) , but it still runs poorly.
>   Here are the other things I've done:
>
> Checked fuel pressure (30 psi), swapped fpr to be sure.
> All voltmeter/ohmeter checks at the ecu connector per Bentley OK.
> Cleaned ecu connections, checked and cleaned all grounds, replaced ground
> strap from left head.
> New plugs, wires, cap, rotor, installed afm harness upgrade.
> Replaced temp sensor II- checks out OK with ohmeter.
> Swapped from good-running van: ecu, afm, coil, idle control valve.
> Emptied contents of converter to make sure it wasn't clogged.
> None of the above new parts or swaps had any effect on performance.
> A voltmeter on the oxygen sensor shows predominantly 0.8-0.9 v. with the
> usual fluctuations, so the sensor is definitely trying to tell the ecu that
> it is too rich.  Disconnecting the oxygen sensor has no effect on the way
> it runs that I can discern.  I'm starting to be suspicious of the main
> wiring harness but replacing that on the syncro will be a major
> job-probably will require dropping the gas tank and tranny.
>
> The engine is not in great health, but I don't think it's bad enough to
> blame for the poor performance.  Compression is 135-135-90-120.  Head
> gaskets had apparently been replaced (but not heads) by a real schlock
> mechanic-when I got it the ground from ecu to engine was disconnected, and
> the protective covers over the pushrod tubes were missing.
>
> I've gotten lots of advice from people on the list already, special thanks
> to Darrell Boehler and Kyle Wade, but I'm still stuck.  Any ideas are very
> much appreciated.
>
> Bill
>
>