Date: Mon, 17 Mar 2014 18:38:23 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Help. traveling with problem
In-Reply-To: <F3E72A7A-DAE0-47EF-AB87-EF71FD74B44F@gmail.com>
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Sounds like you have a problem with the O2 sensor or circuit. Are the plugs carbon or oil fouled?
There are a number of checks you should make to ensure the wiring to the sensor is good. A common problem is the ground reference for the O2 sensor. This is shared with the distributor. On the 87 Syncro it is common for this ground to be attached at the base of the oil breather. Plastic does not make a good connection. Replace the ring terminal if there is any sign of corrosion even on the wire and relocate to something metal such as the fuel pressure regulator bracket. The green wire is a coaxial cable with the outer shield being grounded. Pull the insulation back. With a good meter handy you want to check the integrity of the wiring. O2 sensor disconnected ignition, on, engine not running check voltages as follows. Signal lead to chassis, ~.5-.6 volt. Outer shield to chassis, real close to zero, outer shield to signal lead, .5 to .6 volt.
Start engine. After a few minutes check sensor to ground. Should be some voltage. Richer mixture higher voltage. Connect signal lead to chassis, engine should run richer. Connect a battery (C-cell) positive to the signal lead, negative to ground, engine should lean out. If O2 Sensor is working you will see the changes on the meter the meter.
Final test, reconnect o2 sensor and start engine. After a minute or two O2 sensor should gain control. Connect meter to sensor lead and ground. Ideally voltage should swing from ~.2 to .7 or.8 volts repeatedly.
Since the plugs were carbon fouled it is likely the sensor is also. The catalyst also does not last long like this.
If a new sensor is needed a FLAPS should be able to help. There should also be a deflector/heat shield on the sensor to keep air flow and debris away from it. Most are missing.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Chris S.
Sent: Monday, March 17, 2014 5:18 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Help. traveling with problem
First step: unplug the O2 sensor and see if it runs better.
Check your dizzy and rotor button.
It could also be that the plugs are shot.
Chris.
Wysłane z iPhone'a
Dnia Mar 17, 2014 o godz. 17:02 Kk Al <kkalnsf@GMAIL.COM> napisał(a):
> Hello all
> We are in the middle of our vacation traveling in our 87 Synco. The
> van has been running very well untill all of a sudden it started
> missing on the freeway. We pulled over and did a visual inspection.
> Everything looks ok. I pulled the plugs and found theky are all fouled.
> Once we started bwck up everything worked for a few minutes and the
> missing started again.
> We have noticed the problem goes away if we keep the accelorator on
> the floor . If also goes away for a few seconds if we let off the
> accelorator and reapply The problem arises when we how the accelorator
> steady.
>
> Any help is appreciated. I'll be checking email frequenly
