Date: Sat, 28 Apr 2001 11:40:31 -0600
Reply-To: Steve Blackham <steph@uswest.net>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Steve Blackham <steph@uswest.net>
Subject: Re: Fuel Injection Adjustment
In-Reply-To: <3AEAECEA.7167D022@islandnet.com>
Content-Type: text/plain; charset="us-ascii" ; format="flowed"
Thanks Mark
I appreciate your info. Vacumn leaks would cause a lean situation.
I'm too rich. Not enough air getting to the combustion chamber or to
much fuel. I think I'll start with the AFM and clean the idle bypass
passage first. Then check the exhaust system for small leaks. They
cause the O2 system to think its to lean and richen the mixture. A
small enough leak would show up at idle and the pressure of a full
exhaust would eliminate the leaking in air at a throttle.
The Temp 2 sensor is fairly new but merits a check as I think its
still to long for the engine to warm up and go to the O2 cycle.
I know the cat is a straight tube but it shouldn't effect the
capability of getting to factory idle settings which are usually
taken ahead of the cat.
Last, because of the labor required, I'll check the individual
injectors for flow and leaks.
Could this be a ground problem by chance. Normally I would think
that would cause a lean situation (no input to actualte fuel) but I
don't know?
Thanks
Steve
>Hi Steve,
>
>I also wanted to mention a couple of other little variables that could
>influence your readings.
>
>The rubber seal at the dipstick and consider adding a hose clamp where
>the plastic oil filler neck slips over the metal oil filler tube- it's
>junction is right in them middle of the alternator belt's path. It
>seems that these two items have a tendency to allow "false air" to enter
>the system, that why they are sealed. The oil filler is just a friction
>fit over a raised lip in the steel pipe. Since they are source of
>additional un-metered air their effect is a lean idle.
>
>Also on the emissions side of things, crankcase oil can have gas in it
>which also would be
>a false reading point. I think this last point get's overlooked, but it
>seems I read a considerable number factors that need to be address, but
>basically baby the oil until your done testing. Avoid lots of cold
>starts without letting the engine oil recover from the rich mixture, the
>testing instructions in your CO meter may address this too. An oil
>change along the way could give your more accurate readings too.
>Sincerely,
>
>Mark Keller
>91 Carat
>Cowichan Bay, BC