HI Scott.

On Wed, Oct 13, 2010 at 10:46 PM, Scott Daniel - Turbovans <
scottdaniel@turbovans.com> wrote:

Is your ABA engine OBD-I or II ?
> Do you have an OBD diagnostic port ?
>

OBD1 and yes.

Oddly, though the pin was present on the ECU, there was no MIL wire in the
harness. I installed one. IIRC, Bentley notes that some early years (93'
IIRC) didn't c/w this wire in the harness.

> the OBD-I systems I am familiar with generally use counting flashes of the
> Check Engine light to get out basic OBD- I  one codes.
>

VW OBD1 uses flash codes too. Possibly limited to '93 and '94 MY. Jumper
pins in the port and read the flashes.

>  The Haynes manual on OBD-II is quite good reading, btw.
>

Good to know. I'll keep an eye out for it. Had looked on line for more info
at one point.

>
> the OBD-II code reader I have now doesn't even have a way to interact with
> OBD-I that I know of.
> I find codes useful ..
>

Hmm..... thanks.

>

intermittent anything  just tells me that circuit might be weak or wonky.
>
> Thanks for mentioning RossTech  freeware ,. perhaps I'll get me some.
>
> the pic looks like an OBD-II connector to me, the big part.
>

Yes. It has "OBD2" stamped on it.

btw, here's a link to a page on Ross Tech showing differences between the
free version and other versions:

http://www.ross-tech.com/vag-com/vag-functions.html

> I always start with the symtoms ......then start checking things.  Most of
> the time I can find about 3 or 4 or more,  half-not right things on most
> engines that don't behave well that I see.
>

Thing is, it runs fine. But sometimes, I swear it runs *slightly* better
than others. (slightly more power, better acceleration)

On Jasons suggestion, I suspect the big 28 pin connector may have an
intermittent connection, or, two or more wire casings in/out of it may be
cracked a little and shorting. I checked and cleaned it again and relieved
some of the tension on the wires by repositioning it. It was somewhat
twisted and I suspect that if there was a slight crack(s) in a wire casing
maybe it was shorting out there. This harness had many flaws in that regard.

Pic or connector: http://sites.google.com/site/tubaneil2/28pinconnector2.jpg

Neil.
--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"

http://tubaneil.googlepages.com/

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