Date: Fri, 21 Jan 2005 11:15:46 -0800
Reply-To: Craig Oda <craigoda@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Craig Oda <craigoda@GMAIL.COM>
Subject: Re: Driveability issues with a non-stock engine
In-Reply-To: <20050121032245.94013.qmail@web53510.mail.yahoo.com>
Content-Type: text/plain; charset=US-ASCII
Damon,
I don't know too much about these things. However, if I were forced
to try something, I would set the AFM to be slightly artificially
rich. I think engines are generally more sensitive to lean conditions
than rich conditions.
Try tweaking the wheel in the AFM so that the O2 sensor is reading
0.6VDC with the O2 sensor disconnected from the ECU harness.
I have a wire running under my van that connects the output of the O2
sensor to a digital voltmeter on my dash. I can monitor basic
air/fuel mixture while the van is running under different conditions
like cold and throttle.
You might kill your O2 sensor if you run it rich for too long, but if
you can get it running off of idle, then you can tweak the air/fuel
mixture back down.
It should be running rich at wide open throttle.
I find that my O2 sensor on my 83 waterboxer takes about 4 minutes
before it's warm and operational in northern cal.
I used to think I had a vacuum leak for the longest time. Maybe I do.
But, I never found it. At least I can get the van to idle after
adjusting the air/fuel mixture.
My life before air/fuel tweaking:
- van would not idle consistently
- could not reverse properly since low rpms would kill the engine
- stopping at stop lights sucked because I had to drop the van in
neutral and keep the rpms up
- when engine was cold, I would have these funky situations where I
would press the accelerator and the van would have no power. Then,
the power would suddenly kick in after 5 seconds. irritating.
My life after tweaking
- I drive it to work every day and it somehow gets me there and back
- before I turn the key, I always wonder if it will start, but it somehow does
- I no longer worry about reversing out of the parking stalls at
Safeway and thus have more food in my house
- I have power throughout the powerband. Well, with a 1.9L
waterboxer in a heavy Westy, "power" is a relative term.
- there are still many problems with my van to keep me from a life of boredom
Good luck.
-- Craig
On Thu, 20 Jan 2005 19:22:45 -0800, Damon Campbell
<damoncampbellvw@yahoo.com> wrote:
> Hello wise and all-knowing list... i have a troubling
> question (to me) to pose (to you).
>
> Currently, my '84 westy is running a 2275 WBX. Stock
> pistons, stroked to 82mm, and running big-valve heads.
> Fuel injection is stock 1.9 Digijet. The problem is
> that it ironically lacks power, and has little (and
> sometimes NO!) power when accellerating from a dead
> stop.
>
> I have the digitool hooked up, and primarily it is
> telling me that the engine drops full lean when coming
> off that dead stop (or just really low RPMs). This
> can last 10 seconds or so, until it ever so gradually
> creeps up in speed. To get around this, i've been
> working the clutch to keep above the seemingly magic
> 2k rpm range where it really perks up.
>
> For general drivability, once i get going, the van
> surges under moderate to heavy throttle. It is smooth
> (and seems happier) at very light throttle. O2 sensor
> oscillates around .5V, unless you goose it, at which
> point it generally dips lean, but readjusts to .5V.
> If you disconnect the O2 sensor, the surging goes
> away, but it loses even more power.
>
> I've checked the FPR, which seems good. The injectors
> are recently serviced, and a vacuum leak check showed
> no leaks (used propane to see if the idle rose). The
> O2 sensor has about 6k miles on it.
>
> The kicker is, the AFM adjustments are completely out
> of whack (spring and idle). This has been tweaked on
> (initially by BusLab down in Berkeley, CA), and now
> vainly by me in an effort to trick the 1.9AFM into
> liking the 2275.
>
> Other possibly useful information is that on a
> previous (and similar) engine to this one, it was
> dialed in and ran like a bat out of heck.
> Unfortunately it died (my build error), so this is
> it's replacement. All FI components are the same, so
> i am pretty sure i should be able to get this to work.
>
> Do any of you have some advice on things to check for?
> I am getting quite worried, as my parents are coming
> to borrow the van for a month as they drive from
> Vancouver, Canada, down to Arizona, and i don't want
> to stick them with a lemon. It would probably make
> it, it just wouldn't be any fun.
>
> Thank you for any insight you may give me,
> -Damon
>
> =====
> '84 Westy (Sparky) w/2.3L WBX
> Vancouver, BC
>
>
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