Matt Heydon wrote:

> To the group:
> I have an '87 Westy that as I tool down the road it feels like someone is
> tapping on the brakes.  I don't know how to tell if the condition is spark
> or fuel delivery related.  I have replaced the fuel filter and cap / rotor.
> Any ideas would be very helpful and appreciated.
> Matt

You might check your idle stabilizer valve. Disconnect it, Drive it a while. If
the bucking is gone, then you know. If it bucks again when you reconnect it,
then you know for sure. At that point, with the ISV disconnected, adjust your
idle speed to 850-900 RPM, then reconnect the ISV. Drive it. If that didn't
take out the brake-tap feel, go to the right side of your vehicle, remove the
taillight assembly, and look in the opening, and locate the ISC or Idle
Stabilizer Control Box (you will need your Bentley). Remove it, then
reinstall.(a cleaning process of sorts). Drive the vehicle to check
performance. If that didn't take care of the problem, you will need to expand
your search. A check of wear and corrosion on the AFM wiper may be in order.
There are many other things as well.

Good luck,

John Rodgers
88 GL Driver