Loretta, Rich and other Listees,
Two more things you might try:
1) disconnect the Idle Control Relay. You can do this right on the Idle
Control Valve. On our syncro Westfalia we found that as the ICR was
dying, it was sporadically opening the idle control valve even at
highway speeds. This was causing our Digifant ECU much confusion.
2) the injectors are supposed to be seated and sealed in the head by
small rubber gaskets. On ours, these gaskets were leaking air. When the
air leaked in, the OXS read higher OX so the Digifant ECU increased
fuel, the engine revved up, sucked the injectors in tighter, cut off the
air leak, the ECU reduced fuel, the engine revs decreased, the air
leaked and the cycle repeated = bucking. To test this possibility, put
your hand on each injector and wiggle and press it into the head. If you
have any change in revs, you found the air leak. If you find a leak, let
me know and I'll describe how I fixed mine.
Hope this helps.
Larry

Loretta Abbott-Kennon wrote:

> Rick and list members,My Syncro is doing the same thing and the
> mechanic has not been able to fix it.  We have replaced the AFM,  idle
> control valve and circuit, checked for vacuum leaks, and still the
> damn thing "bucks"!  I am eager to find out what the problem is and
> fix it!  I was so excited to buy this van and take it on my big 6 week
> camping adventure.  Then this problem developed, and I ended up taking
> my other van.  I am back from my trip now and have to sell one of my
> vans.  I really want to keep the syncro, but the other one runs so
> good.  Please somebody out there on the list help shed some light on
> this problem!Thank You,Loretta87 Syncro90 GL

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