Cutting out/dropping RPM

[Jitters]

Hi all, my friend has a '87 Wolfsburg Edition. He has spent 4 years (!) trying to fix this problem. Anyone out there who has the answer, puh leeze tell me so I can pass it along.
He will be driving for 45 minutes- one hour, engine running @ 4K, then it just cuts out. RPM's drop to about 3200 to 3000 then after a bit it picks up. He has cleaned/replaced microswitches, and had zillions of dollars spent at the repair shop. It still happens. Any clue? Thanks!
_________________
To be blinding or invisible, nothing in between.

[earthmuffin]

This could be caused by any number of things as I'm sure your friend has figured out. The digijet and digifant systems are both very suseptible to wiring problems. These problems can be bad grounds, corroded connectors, etc. I would recommend doing some searching on the vanagon mailing list archives as there are other people who have encountered this same problem. http://gerry.vanagon.com/archives/vanagon.html
I would also recommend getting a Bentley manual and a multi-meter. A guy with minimal skills can test the entire system with these two tools and a little patience. Unfortunatly, intermittent problems are hard to nail down and sometimes you have to start shotgunning components. The ignition stabilizer and air flow meter seem to be common fixes to this problem. Hope this at least gets you started.

[Amskeptic]

My old '89 Vanagon GL did that trick on Interstate 80 at 43* below zero back in 1992. We thought we were all going to die that night. But it never did stall, and it never happened again. The dealer told me the Digifant ECM had a "bug" in it that they never satisfactorily tracked down.
Colin
( I'm glad I kept my carburetted Bus, but that Vanagon had major beautiful heat.)

[j8]

as a late model vanagon owner, i read that description with a sick dread. the vanagon list has tons of archive links to the "vanagon syndrome" fix.

<knocking on wood>

best of luck to your pal.

[earthmuffin]

Found some more info:
http://www.benplace.com/vanagon_intermittent_syndrome.htm

[Tram]

hi-
The official VW Fix for your problem (referred to by VW as "Mystery Miss") is as follows:
1) NEW Bosch airflow metre (NOT used, NOT rebuilt.)
2) Run an auxiliary ground wire from the body of the AFM to ground. There's a threaded hole on the side of the AFM for this purpose. CLEAN ALL GROUNDS in the engine compartment and make sure they are TIGHT while you're at it. MAKE SURE ignition timing is correct.
3) Ask your VW Dealer for the upgraded airflow metre pigtail. It plugs right in BETWEEN the original connector and the AFM. For good measure, install a new airfilter. The Syncro filters are a heavier duty element, but fit BOTH Syncro and non syncro models.
4) Don't worry, drive happy.
It's not a cheap fix, but it is THE fix. I went to many VW schools on Vanagon Mystery Miss, which affects the '86- on models (2.1 Litre). I've successfully fixed hundreds of them this way. Incidentally, this problem occasionally rears it's ugly head on Jettas and Foxes with AFMs, but not too often. The fix for those is the same, MINUS the pigtail.
Hope this helps. The other ugly Vanagon problem is leaky, corroded cylinder heads. If anyone has THAT problem, I can tell you how to FIX your heads. No sheet!