Date:         Fri, 22 Sep 2017 08:51:05 -0700
Reply-To:     Alistair Bell <albell@SHAW.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Alistair Bell <albell@SHAW.CA>
Subject:      AFM cap fix, maybe fixed my very intermittent problem
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I’m not completely sure that adding the capacitor to the AFM has solved the problem, but so far it looks like it has.
Background, for about 5 years I’ve had a very very intermittent running issue with the stock 2.1 motor in my Syncro. Symptoms would be bucking and hesitation when applying throttle. At wot the bucking would stop. At idle, motor ran fine.

This only happened on summer trips, mostly rough logging roads. Occasionally it would happen on hwy when returning from rough roads.

Sometimes the problem would come and go within a day. Every time the problem would be gone the next day when back in town.

Never happened around town, never happened in winter. Never happened on long summer Hwy trips.

So it never quite fit the pattern I had read about regarding the classic vanagon syndrome.

Over the years I had redone all the elect connections to the motor. I had swapped in spare coil, spark plug leads replaced, plugs replaced, fuel filter, temp sensor, rotor, Hall effect sensor checked, new O2 sensor , etc etc.

And due to the very intermittent nature of the problem, troubleshooting was pretty well impossible. I would have no idea if any work I did had any effect until the problem came back... on a trip.

Happened again on the first trip this year. Hot weekend, rough roads, issue occurred on the Hwy on return trip. Issue went away about 4 km from home. 

Just for the hell it, after that trip I soldered a 22 microfarad tantalum cap between two leads in the AFM. Details on the net, you guys know.

But, at same time I cut back wire on the ground that’s on block adjacent to the dist. Wasn’t broken and I had redone the terminal some years ago, but the insulation felt hard... couldn’t help myself. Does muddy the waters a bit though.

Upshot is the bucking and hesitation issue did not happen again all summer. And we did go on some rugged trips in very hot ( for here anyway) weather.

Honestly, I don’t know if the problem is fixed. I’m leaning that way though.

Alistair