[Healeys] Rostra Cruise Control

[R. Price Lindsay]

Listers -

As background, I have recently installed an alternator and pertronix ignition
system in my late model BJ8.  There are no other bells or whistles on the car.
I am now in the process of installing the Rostra 250-1223 Cruise Control unit
along with the 250-3592 switch and 250-4165 signal generator.  I have followed
the wiring and installation directions very carefully and everything seems to
work fine except the car "surges" when the cruise is engaged.  I have tried
several "switch" changes to tune the throttle control but it still surges when
engaged.  By "surge" I mean the car will speed up to the set speed, then coast
for about a second and then surge back to the set speed over and over again.
I have talked with the tech folks at Rostra several times but can't seem to
find a solution.  They tell me it is my car to blame. The latest suggestion
was to ground the unit directly to the negative side of the battery, I presume
to avoid electrical interference.  I did this, but no change.  I did not
ground the control switch to the battery, just the cruise module; could this
allow the interference I'm trying to avoid?

Any suggestions or the contact information of someone in the "know" about
these units would be greatly appreciated.

Price Lindsay
67 BJ8