Skip to main content
Gerry | Vanagon
Checking account...
← vanagon.com home · Continue the discussion in the forum
Subject:Re: CO Adjusting Screw. PO Set it All The Way In? Base Setting?
From:neil n
Date:Thu, 21 Jun 2012 14:17:53 -0700

Thanks Mike. 1.5 turns. Ya that rings a bell.

Adjusted CCW 3 turns. Engine warm, starting on slight incline, usual
light-foot-on-gas clutching technique, stalled 3 times in short distance.
Set to 1.75 turns, didn't stall. (oh so highly scientific)

Archives suggest an incorrectly set CO screw could damage the engine. But
since it's an idle setting, what engine damage would a too rich or too lean
idle mix do? Maybe it would happen over a long period of idle time(s).

On thesamba, someone suggested my old plugs (prior to my work) showed a
rich mix. Maybe due to a bad O2 sensor and/or 1/2 clogged cat but likely
mostly due to an incorrectly set CO adjuster.

It now surges less overall coasting in gear to a near stop. Yesterdays AFM
wiper adjustment may have helped this too.

Neil.

On Thu, Jun 21, 2012 at 12:34 PM, Mike S <mikes@flatsurface.com> wrote:

On 6/21/2012 2:36 PM, neil n wrote:
>

>  .... Checked CO screw
>> setting. It's all the way in.
>>
>
> That can't be right, unless it was adjusted to make up for a vacuum leak
> elsewhere. It's just an air bypass adjustment, to let air go past without
> being metered.
>
> Unless I have documentation otherwise, any adjustment screw which I know
> is screwed up, on any carburetor or FI system, is always "in till tight,
> out 1 1/2 turns" as a starting point. :)
>

--
Neil n

65 kb image Myford Ready For Assembly  http://tinyurl.com/64sx4rp

'88 Slate Blue Westy to be named.

'81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/

Vanagon VAG Gas I4/VR Swap Google Group:

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines