Date: Tue, 20 Aug 2002 20:25:15 -0700
Reply-To: Doktor Tim <doktortim@ROCKISLAND.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Doktor Tim <doktortim@ROCKISLAND.COM>
Subject: Re: Not passing smog, still... Need help!
In-Reply-To: <FCEEIGDOKPNNIFBPGKDJEEMBCNAA.steven@epochdesign.com>
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At 04:59 PM 08/20/2002, you wrote:
>My ex-mechanic claimed to have done a lot of stuff, like checking
>compression. When I removed a plug, I found that the plug was dirty and gap
>was about .070", turned out all of them were like that. Also, the plug wires
>were in pour condition. You'd think that if they took the plugs out to check
>the compression, they would have seen or noted the plug and/or wire
>condition. This leads me to believe that they may not have done all they
>said they did during the 2.5 weeks they had Inga.
I can do a very thorough engine maintenance inspection in 3 hours or less,
including compression. Up to 2 hours to do compete computer systems
diagnosis in the cases where maintenance does not resolve the problems.
That's an absolute maximum of 5 hours. The bad plugs alone say don't go
back. When you add it took 2.5 weeks, well, that's just ridiculous. There
are several steps involved in setting the timing and mixture. See the
Bentley. If you don't follow the procedures, you will get false readings.
Is this supposedly a VW specialist??? Sure doesn't sound like it.
>The problem/s?:
>The smog is failing the idle test with HC running between 220-280 (150 max).
>If I adjust the CO screw, it corrects the problem, temporarily.
So, do that and pass inspection, then reset it. But that doesn't resolve
the problem.
> Could it be the Ox
>sensor?
The setting of the CO requires the sensor to be disconnected, which is
called open loop. The base idle as well is set with the automatic idle
control deactivated. Some of those pesky steps I was talking about. Others
are, disconnect the temp sensor, remove and block the crankcase breather hose.
If the plugs were fouled with carbon, so is the oxy sensor. After setting
the CO to spec in open loop, hook the oxy back up and monitor with a VOM
(closed loop). It should fluctuate rapidly from 0.3 to 0.7 volts. If there
is no flux or slow flux, the oxy is toast. Something else. Cats don't just
go bad. They are destroyed by the motor running out of spec. If you don't
fix that, you can fry the new cat.
> I will test that out tomorrow. When the throttle is released, the
>rpms go down to about 1100-1200 for a bit (10-30 sec) and then finally drops
>to 850-900. Would the idle stabilizer cause this?
Clean the crankcase breather and the throttle body. From what you said
about the mechanic, I would sure as hell want to verify the very first
thing, compression. I don't trust that he knows how to do that. He sure
seems to have his exhaust gas equipment out of calibration, or doesn't know
how to use it. Does he even own a Bentley??? Sure sounds like he's just
winging it and pokin' screwdrivers.
Also, know that the spec plugs are not generic. They are of a special
electrode design. Bentley gives the correct Bosch part no. for your motor.
It will be either a W7CCO or W7DTC. Use it, I don't care that they cost 3
times as much as the Supers. They were particularly designed to function
properly and with long life with the specific motor and ignition system.
