Date: Fri, 30 Jun 1995 10:50:49 CST6CDT
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: "Dan Houg" <fairwind@northernnet.com>
Subject: Re: Emissions Failure
There has been some good suggestions so far. He's my 2 cents worth.
False air leaks. this was mentioned and DO check this out (stuff in
archives). your dealer said the engine ran 'too good'. this is
probably a reference to a smooth idle, which seems to mean over-rich
on these engines.
ECU grounds. yada yada yada. they make a difference. find 'em and
clean 'em up.
Plug wires. I didn't see mention of plug *wire* replacement. they
go bad quickly on these engines due to high heat, road grime, and a
Bosch conspiracy.
Spark plugs. There are documented cases where the only difference
between and emission failure (with new regular electrode plugs) and
emission pass was the installation of tri-electrode plugs. Now
here's the kicker: there is not a dealer listing/vw application for
the tri-electrode plug for the 2.1L engine. there is for the 1.9L
and just about every vw engine in current production but not the
2.1L. I can't for the life of me figure out why they dropped the
tri-electrode from the application for this engine. They made a
noticable difference on my 1.9L. I really wanted to stick a set of
tri-electrode in my 2.1L but was scared off with thoughts of
piston-plug clearance etc. Somebody help me out here.
Change your oil. If your oil is real old or for some reason got
diluted with gas, you'll get out of this world emission readings.
Exhaust system leaks. a crack in the exhaust BEFORE the O2 sensor
can suck in air during an exhaust pulse and make the sensor think the
engine is lean, hence it richens itself.
Throttle switch. oh, yes. check that puppy out.
Since a wise list member said the fruit is on the END of the limb,
i'll go out there and say that it's NOT your ECU, basic engine, air
flow meter or any of that other horrible stuff. It's time to spend
some obsessive time with the basics. A dealer won't (and you
probably couldn't afford it if they did) do it right 'cause it will take time
cleaning grounds, checking for air leaks, etc.
Hey! do you think i could start a radio show making sweeping
generalizations like this? Naw, nobody would ever listen to it... :)
-dan