[jeffbottman]

I've resurrected my cruise control to some extent ('86 Targa) by reflowing all the solder joints and replacing the two large Al electrolytic caps, which were bad.

Trouble is, the speed ends up ~5 MPH above the 'set' speed (surges initially), and then alternates speeding up and slowing down over a few MPH range, as though the hysteresis of something in the circuit is too wide.

Any ideas or insights out there on how to proceed? I am thinking of replacing all the tantalum electrolytic caps also. The ICs, resistors, and film capacitors should not be troubled by age.