Date: Thu, 10 Aug 2006 14:24:03 -0600
Reply-To: alfred bagdan <abagdan@SHAW.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: alfred bagdan <abagdan@SHAW.CA>
Subject: Re: 1000 mile rebuild recommendations?
Content-type: text/plain; format=flowed; charset=iso-8859-1; reply-type=response
Just a thought.
I once had a rebuilt air flow meter that stuck in the open position. Van
run very rich and also kept stalling. Open the AFM and make sure the arm
swings back and forth freely.
Alfred
----- Original Message -----
From: "Michael Diehr" <md03@XOCHI.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, August 08, 2006 5:06 PM
Subject: Re: 1000 mile rebuild recommendations?
> Hey Dennis, thanks for the info. Here's a more detailed description
> of the problems:
>
> My AFM is newly rebuilt, and the O2 Sensor is brand new, and the ECU
> computer is "new" (e.g. a supposedly good used one). 85 Westy
> automatic tranny, rebuilt with 1000 miles on it.
>
> O2 sensor disconnected -- van idles and runs great at all
> temperatures & speeds, but gets poor mileage.
>
> O2 sensor connected -- Cold start : van runs fine. Hot : runs
> fine. Warming up: as it heats up (perhaps 2 to 5 minutes after cold
> start) it tends to stall at idle, and will sometimes stumble upon
> acceleration. If I adjust the idle adjustment screw to prevent the
> low idle when it's warming up, then when it's hot, it idles too high
> (around 1500rpm) and surges upon deceleration.
>
> The rebuilding shop, and another shop both had trouble getting it
> "perfect", but I don't have great confidence in either shop. The
> rebuild shop told me to run w/o the O2 sensor, the other shop totally
> missed the fact that the O2 sensor was damaged.
>
> Any ideas? My main concern is that perhaps with the O2 sensor
> hooked up, it's running dangerously lean and could lead to damage...
>
>
> On Aug 3, 2006, at 10:29 AM, Dennis Haynes wrote:
>
>> Running with the O2 sensor disconnected is non sense. If you are
>> seeing a 3 mpg improvement wit it connected, then you are running
>> rich and if done long enough, you might as well the catalytic
>> converter good bye. A hesitation on take off is a common Vanagon
>> malady that may need troubleshooting, but disconecting the O2
>> sensor is not a fix. If the O2 sensor is working, the only
>> adjustment is the idle bypass. The mixture screw on the air flow
>> meter has no effect above idle. Any further adjustment is really
>> tampering. As far as running rich being good for a rebuild, I fail
>> to see how excess fuel washing off the oil or leaving some soot
>> behind can be of any good.
>>
>> Dennis
>>
>> ----- Original Message -----
>> From: Michael Diehr <md03@XOCHI.COM>
>> Date: Thursday, August 3, 2006 12:05 pm
>> Subject: Re: 1000 mile rebuild recommendations?
>>
>>> Thanks to all who responded.
>>>
>>> No, I didn't get any documents with the rebuild, other than a
>>> bill. :(
>>>
>>> It sounds like the consensus is, for 1000 miles, an oil change for
>>> sure, and valve lifter adjustment maybe (but perhaps only if they are
>>> noisy?).
>>>
>>> Second question: I've been running with the O2 sensor disconnected
>>> as per the installing mechanic's recommendation. I'm a little fuzzy
>>> on his reasoning, but I think it was a combination of the idea that
>>> running rich was good for a rebuild. With the O2 sensor connected it
>>> seemed to be running lean, and it wasn't worth adjusting the mixture
>>> since the piston rings etc. needed time to seat in anyway, so it was
>>> better to just run rich for 1000 miles and then adjust it later. Is
>>> this nuts or was the mechanic just b.s.-ing me?
>>>
>>> In any case, I'm at 1000 miles, so time to move on. If I leave the
>>> O2 sensor disconnected, the van runs great, but only gets about 14mpg
>>> on the highway and is probably laying waste to the environment.
>>> With it connected, it gets around 17-18, but has moments when it
>>> stumbles on acceleration. The O2 sensor is new.
>>>
>
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