Date:         Sun, 8 Jul 2007 16:06:39 -0400
Reply-To:     Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
Comments:     RFC822 error: <W> MESSAGE-ID field duplicated. Last occurrence
              was retained.
From:         Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject:      Re: A bit rough idle, running. Unbalanced injectors?
Comments: To: Martin Jagersand <jag@CS.UALBERTA.CA>
In-Reply-To:  <e3e1d7f0707080900k1ce3da1bj501155e0ad5ff7f1@mail.gmail.com>
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I would go for a bad ignition wire first. The wires are usually OK but the
resistor ends by the spark lugs are hi failure items. They can both open
and short to the engine. An inductive timing light can often find the
offender. The bad wire won't fire the light.

Dennis


-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Martin Jagersand
Sent: Sunday, July 08, 2007 12:01 PM
To: vanagon@GERRY.VANAGON.COM
Subject: A bit rough idle, running. Unbalanced injectors?

Hi all,

I have a question about a gas engines rough idling and running.
This is my '94 Westy, so its the I5, but I imagine the 4cyl can
have similar symptoms/problems also.

Symptoms are:
Rough running. Not misfiring, but just rough.
Particularly noticeable as a vibration at idle (but motor
mount ok), but also noticeable at speed and as a rough sound
when accelerating.

I think the Westy also has somewhat worse gas mileage and
less power, though that I haven't measured this objectively.

Trouble shooting I did:
I checked spark plugs and they are all good.
I couldn't localize it to a particular cylinder by pulling one
spark plug wire at a time.

Compression good on all cyl.

I checked temp sensors, and startup sequence. As far as
I see it behaves normally. (At startup has 1000rpm high idle,
warms up, drops to about 850. Two temp sensors change
Ohm-value correspondingly. Both rpm stable, but running at
both are a bit too rough.)

Neither the VW dealer, nor another local shop could figure it out.

Having worked only on Diesels my whole life, gas engine
electronic injections and the many ways they can give trouble
is beyond me, so I'm hoping for some advice.

Could it be just unbalanced injectors? Tried running a couple of
tanks with injector cleaner, but didn't help.

How difficult is it to pull the injectors on the Eurovan Westy?
I can't see them looking from the top. I could try do it myself
or take it to a garage.

Anyone knows of a good Canadian injector service? (I found several
US web sites, but would hate have my injectors delayed in customs.
I don't have a second set)

Thanks for any advice.

Martin
--
Martin Jagersand
University of Alberta
http://www.cs.ualberta.ca/~jag/