Re: [T3] Art Sterrett's Brain

[Jim Adney <jadney@vwtype3.org>]

On 26 Sep 2006 at 8:26, Matthew Jones wrote:

> http://members.rennlist.com/pbanders/ecu.htm#D1-D2

This is really good stuff. His 'scope views show exactly what I would have 
expected (once I realized that there is a 6 Ohm resistor in there.) There's 
more good info here, too, but I haven't had time to go thru it all yet. It's  
nice to see that someone has actually done this. 

If you look at the photo of the 3 exposed brains, the one on the left resembles 
the 311 D brain that I repaired last week. I THINK the fuel pump control 
transistor is there, but it has this black heat sink mounted on it that makes 
it virtually invisible in this photo. If you want to try to find it, it's on 
the lower left corner of the main board. In that photo it just looks like a 
black area with nothing there.

Our A and B brains have that transistor in the same location, but without the 
heat sink or foam pad. My guess is that '68-9 cars won't ever have this 
problem.

The fuel pump control transistor has been moved in the later models with the 
larger daughter board. Our later 311 E brains also have that larger daughter 
board, but don't have the CO potentiometer. You can see a transistor with the 
"right" kind of black heat sink in the large photo of the late brain. That 
transisor is located on the lower right side of that board, just below the 2 
silver rectangular boxes, which are capacitor snubbers for the injector driver 
transistors.

Now that I know where to look, I'll have to get out a flashlight and look down 
in one of my 311 E brains to see if they still used that little foam pad under 
that transistor.

-- 
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054
USA

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~