No one here can know for sure what is your problem, it could be 50 different
things! The ECU (computer) take it's imput from 3 location; 1 is the temps
sender (blue), it's located on the left side of the throttle body, if you
don't know the state of this one, change it (it's a must anyway)! When
there, clean the connector with "Brake Cleaner", this will will remove any
trace of humidity. The second one is the OS sender, if you don't know the
story about this one, change it. This one can also be unplug and the engine
will still run fine, so you can unplug it and do some test. It's location is
on the right side, under the coil, look for a green wire, single connector.
The third one is the AFM/AFM temp sender, the AFM is attach to the air
filter box, this one is expensive and impossible to unplug. The engine need
at least the AFM and the temps sender to work properly.

If you know a nice and honnest mechanic around your neighborhood, go and see
him and ask him to swap parts wile the problem occur.

I acustomer came to my shop with a very high idle, we swap a few parts
including the idle control box, it was the proplem, 15 minutes, 75$ for the
used part.

If you do that and the problem is still there, it could be in the harness or
in the computer.

I hope that help Ric.
Regards, Ben
http://www.benplace.com/

On Wed, 10 Oct 2007 14:42:00 -0400, Richard Golen <rgolen@UMASSD.EDU> wrote:

>Hi,
>
>
>My 87 Westy has a power loss problem. It occurs when the engine is
>cold and the engine is damp (from recent rain or high humidity), and
>lasts (usually) for about 10 minutes. As I accelerate (partial or
>full throttle no difference) the engine bogs and looses power. If I
>shut the ignition and turn it back on, the problem clears....and then
>comes back until I've driven for 5 to 10 minutes. It also happens
>when the engine is warm and I'm driving through heavy rain.
>
>Anyone know what the problem might be, and what can be done to fix it?
>
>
>Thanks.
>
>Ric