Date: Wed, 3 Jan 2007 17:22:01 -0800
Reply-To: Mark Drillock <drillock@EARTHLINK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Mark Drillock <drillock@EARTHLINK.NET>
Subject: Re: Baffled
In-Reply-To: <00da01c72f91$1b9ee4f0$2e01a8c0@FirstLaptop>
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Zoltan, those readings indicate a bad ground wire for the O2 sensor.
This is a common problem and that is why the newer version of the
Digitool like yours has the setting to read the voltage on that ground.
The ground reading should be 0.00 or pretty close to it.
No reason to fool at all with the O2 sensor itself at this point since
it has good readings. The dedicated ground wire for it NOT located near it.
You need to check the brown wire that comes out of the small bundle
going to the distributor. The rest of the wires go to the distributor
connector but the brown one is normally screwed down to stud near the
distributor. THAT is the O2 ground wire. Many times it is frayed or the
nut holding it down is loose, or the ring is dirty.... Any voltage on
this ground wire gets added to the voltage on the O2 signal wire when
the ECU measures it. That is why it needs to be ZERO because otherwise
the ECU measures the O2 reading wrong and try to compensate the mixture
till the reading is right, which it never will be until the ground is fixed.
Mark
Zoltan wrote:
> Hi guys,
> Happy New Year to all. And when I say guys, I mean the gals too.
> For the new year, I have a puzzle to fix. I am baffled. A friend of mine asked me to help him fix his trouble. I took it on, but I wish, I did not.
> It starts fine, idles well for awhile, then vacillates, hesitates, it dies while driving or while standing at the light, or whatever, until it warms up. Once it warm, it is fine.
> Now, I changed the temp II sensor, the Oxygen sensor, looked at the vacuum lines (although did not check vacuum with gauge), changed the idle unit that's on the top of the engine.
>
> I have also hooked up, using it the first time, a Digitool. I get all kind of readings that don't tell me anything, of course. I don't even know if they are voltages or what. For example, while I'm getting good reading from the O2 sensor at the sensor, it gives me from 1.2 - 2.2 reading. About 1.00 more than I would expect. Or the reading for the O2 sensor ground, which is just over 1.00, up to 1.35. I guess, it should be 0.00. But who knows.
> Anyway, is there one online who would know where to look for the fixing?
> I would appreciate it. Reading the archives did not help.
> Zoltan
>
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