Hi all. Thanks much for the responses.

Of note, the old Jetta ECU I rplaced, had som serious burns on  a few small
components
and a copper ground trace. You can see where this circuit board trace arced
to the multi pin connector frame; it's likely that electricity jumped
the 1/4" gap between these two parts as it may be that this frame part
grounds to the vehicle chassis. Ironically, engine still ran "ok" but has
always had a mysterious intermittent lack of power )felt like timing
retarded) with a more recent slight surge under load at higher PRMs.
New ecu is working fine. Better power, and at last check, 1.5 MPG better
fuel efficiency.

Go figure.   ;)

True, it was risky, and you've made an important point, but when I saw the
circuit board burns on the old ECU, swapping ECUs was a no brainer; I
compare and inspected the new used ECU to old one before installing. Before
firing up the engine with the new ECU, i made sure the fuel pump primed and
that the MIL light came on, ignition on, engine off.

Neil.

PS. thinking now, I recall that in the OEM application, the Jetta ECU mount
bracket may be insulated from the vehicle frame! The way I mounted it in my
vanagon, this bracket is "grounded" to the vehicle frame.

Is this incorrect?

Hope this post made sense. Am using an iPad mini to compose it. Thanks.

On Friday, September 5, 2014, SDF ( aka ;jim lahey' - Scott ) <
scottdaniel@turbovans.com> wrote:

> I'll agree with that too ..
> for welding on the rig....disconnect all batteries and ecu plugs.
>
> Don't know if the rig was running fine on the trip before swapping out
> the ecu ...
> but if it was..
> I sorta have this rule when on a trip ...don't work on stuff unless
> there is a problem .
>

--
Neil n

Blog: tubaneil.blogspot.ca

'88 Westy http://tinyurl.com/c8rlw6p

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

Vanagon VAG *Gas* inline-VR Engine Swap Group:

http://tinyurl.com/d7gd5ej