Pulsing when on Cruise Control

[Hookster]

Whenever I use the cruise control it doesn't maintain a constant speed smoothly. It is basically constantly accelerating and then de-accelerating. Not a lot, but enough to be noticeable. Not sure if this is normal in this vintage ('93) or not. Any input?

 

[Pdwight]

My 94 doees this too

I hope someone chimes in on this, I am on my 3rd cruise module (Amplifier)

 

[Tshark299]

Ours used to do this same thing, many many years ago. Eventually I think a new speedometer cable solved the problem for us. The cruise has been perfectly smooth ever since.

 

[Tony H]

My '91 does it every so often but then goes away for months and months.. I can't fix what isn't broken at the time.

Any Vacuum leaks at the Brake booster?