Date: Sun, 19 Jun 2011 18:14:34 -0400
Reply-To: pickle vanagon <greenvanagon@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: pickle vanagon <greenvanagon@GMAIL.COM>
Subject: Re: '84 1.9L 2-WD -- cold start problems still the same after new
O2-sensor, new Temp II sensor, and new plugs
In-Reply-To: <1308415436.1694.18.camel@landallc>
Content-Type: text/plain; charset=ISO-8859-1
The only other thing that comes to mind is the aux air valve.
This is the little valve that is supposed to be open when the engine is cold
letting in extra air, and then close as it warms up. It has a plug that
goes into it as well, that powers a heating element.
The spring in yours might be worn out, or maybe the valve "door" itself is
gunked up and stuck in place.
I don't think these can be purchased new anymore in the Vanagon part number,
but I think they are interchangeable across old VWs (jettas, busses,
whatever). [warning: I'm embarrassed to say that I know from experience
that it is easy to overtighten the locking nut on the the adjustment screw
and break off the screw.]
But, on the other hand, your aux air valve could be fine, in which case this
is going to add another variable that you'll be fiddling with trying to get
in the right balance with the idle screw setting.
Good luck!
On Sat, Jun 18, 2011 at 12:43 PM, John Lauterbach <
jhlauterbach@bellsouth.net> wrote:
> Cold start problem definition: Engine temperature and air temperature
> around 70-75 degrees Fahrenheit. Start engine w/o foot on accelerator
> pedal. Engine starts and goes to around 800 rpm (instrument panel
> tachometer). If slight pressure put on accelerator pedal to take rpm to
> 1500 or so, and then pedal released, rpm drops to around 300 and engine
> tried to stall and then picks up speed and then tries to stall. Slight
> pressure on accelerator pedal for a couple of minutes or so, solves the
> problem.
>
> Here is what I have done: New within the past two weeks are new
> O2-sensor, new Temp II sensor, and new plugs. A couple of months ago, I
> put in new rotor and cap. Timing is just ahead of the mark. I am also
> working with backup ECU and I have cleaned the contacts on large cable
> going into ECU. I have checked for vacuum leaks and replaced suspect
> hoses and fittings.
>
> Engine is Boston Bob rebuild that I installed in September 2003. Has
> about 40,000 km on odometer. Just about everything I could buy
> new/rebuilt at that time such as distributor and AFM went was replaced
> at that time. A few years ago, I installed a rebuilt throttle body.
>
> Recommendations on next steps would be appreciated.
>
> John
>
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