I am greatly appreciative of all of you, for your help!

It is difficult sometimes to decipher between conflicting views or
diagnosis.
One thing stands for certain, my (ex)mechanic isn't interested and/or
skilled enough to do a good job. I also think that he may have checked one
cylinder (if any) and blown the rest off.

Tim,
I am able to get and even keep the open loop voltage below .5V (or .01V for
that matter), it just floats around too much when I try to set it in the
zone.
I do agree that #4 is trouble and may be the cause of my problems.
I checked under and around and I couldn't find ANY hoses going into any
fitting on or near the top of my air filter. Are there any systems that may
be different? I'll look again.

Dennis,
I have pressurized #4 for 15 minutes with only 1-2psi of loss at ~100psi to
start. Doesn't seem like much loss. Wouldn't the ECU's attempt to compensate
just run the value up to the closest reading and not fluctuate wildly? I ask
because I don't know. You are right about an extension being my best bet.
I just find it hard to put the issue to bed without fight.

Matt,
After careful examination of maintenance invoices of the DPO, I did find out
that this sensor was installed roughly 60K miles ago. It should be replaced.
However, when I talked to the kind folks at VolksCafe, they said the
readings I was getting off the sensor were similar to one nearly new.

Mark,
I will try your valve adjustment test and see what happens.

In the mean-time, I'm  running MMO to see if that does anything. If I can't
get any improved results in the next 48 hours and unless I can just get an
extension for a year, will be spending lots of time on hold with BAR to
discuss the problem and get a referee appointment.

Thanks again everyone for your help and endurance! Any final words of wisdom
are welcome.

-Steven Dodson
Kneeland, CA
"Inga" the 87 Syncro

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]On Behalf
Of Doktor Tim
Sent: Saturday, August 24, 2002 7:27 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Not passing smog, still... Need help!

I strongly suspect that weak cylinder is putting off enough unburned
hydrocarbons that the mean effect is you are out of the range of adjustment
for the system. What is the min spec for compression?? About 102 if memory
serves. You certainly are out of spec for total difference between
cylinders. This creates a situation where the oxy is reading an average of
3 lean cylinders and 1 rich, resulting in the oxy sending false data to the
ECU. The fact that you cannot get open loop below 0.5v verifies the
weakness is beyond the operating parameters of the system.

Now, if your mechanic was aware of the compression imbalance and didn't
recognize that as an issue of high concern, he has not the knowledge to be
servicing Bosch systems. Moreover, if he didn't do a compression test very
early in his analysis, he is incompetent to do diagnostic work. I don't
care if his wall is full of certifications, his actions are definitive in
this regard.

This is why proper procedure requires you verify mechanicals first. If
that's out of spec and you don't know it, you can futz with it till hell
freezes over and never get spec tune. Mechanics who don't follow proper
procedures are a bane to society.

The charcoal hose should be a clear (yellow with age) vinyl hose entering
the motor compartment at the right upper front and running directly to the
upper air filter cover. It fits on a round fitting, about 12mm diameter,
and originally was clamped with a permanent squeeze ear type clamp.

At 06:41 PM 08/24/2002, you wrote:

>Doktor Tim,
>
>The compression is (in cyl order) 130, 128, 132, 98-100 (most likely
rings).
>Fuel pressure is good per test I watched the mechanic perform.
>  I couldn't find the Charcoal hose going to my air filter.