Date:         Sat, 23 Dec 2017 08:45:54 -0700
Reply-To:     Mark McCulley <mark.mcculley@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Mark McCulley <mark.mcculley@GMAIL.COM>
Subject:      occasional hesitation
Content-Type: text/plain; charset="UTF-8"

I'm on a road trip for the holidays, van has been mostly running great but
have had some intermittent episodes of roughness. Hoping to get some
suggestions for things to check when I have an opportunity to do so (single
digit temps today, no garage).

First noticed on beginning of second day, leaving Missoula, just a couple
of hesitations when accelerating onto the freeway on ramp. As long as I was
holding at steady cruising speed, very smooth but if I let off the gas for
any reason, then hesitations again.

I noticed the symptons again yesterday, this time mostly when changing
gears. Smells like it's running rich. Come to think of it I noticed that
smell a few weeks before setting out, well before I noticed any
hesitations.

- The first thing that comes to mind is the TPS, I will check that.
- I have spare distributor cap and rotor, but only 7K miles on the existing
ones.
- I have spare plugs, 17K on the existing ones (W7DTC). Inspected 7K miles
ago and looked fine.
- I have the AFM harness with the capacitor, and have never had a problem
with Vanagon syndrome.

It probably wouldn't hurt to change all those ignition components...

I'm a bit suspicious of the O2 sensor, is there an easy way to confirm if
it's OK? What does ECU do when O2 sensor is unplugged?

Thanks in advance for any suggestions.

-Mark
87 syncro Westy