Mine was mainly caused by a faulty fuel pressure regulator.

  Jeff Woodall
" keep on pushin'"
      woody

> On Oct 8, 2014, at 11:37 PM, Stuart MacMillan <stuartmacm@GMAIL.COM> wrote:
> 
> Travelling to check out a nice looking '87 Westy tomorrow, and seller says
> idle surges.  Been tuned up, new hall sensor and distributor too.  Says idle
> stabilizer hums like it should.  He may have messed up the throttle body
> switch.  Any thoughts on what to check?  I will hook up a vacuum guage and
> look for a disconnected hose.
> 
> 
> 
> Thanks!
> 
> 
> 
> Stuart
>