Cruise control speed oscillating

[kaspr]

Hi,

When I set the cruise, all functions work, except that it doesn't maintain a constant cruise speed. For example, if I set the cruise at 60, it will coast down to 58, and then accelerate up to 62, and then let up again so that it's just coasting back down to 58, and then over again. So basically, the engine never establishes a steady RPM. It's constantly revving up to accelerate, and then going down close to idle for the coast.

Please let me know what you recommend. Also, I was wondering what exactly does the servo do? Could that be the problem. I don't know much about how cruise's work; never taken one apart before. Any help would be much appreciated, THANKS!

kaspr

[deadring]

well im not sure and may be wasting my post but if the cruise relies on something on the tranny like a speed sensor and that thing can get faulty, then if it was malfuntionning just enough to VARY speed a little.. then the cruise has to rely on it.. so if it varies, then the cruise will try to follow it and THINK that it's stable.....that sounds logical


Deadring

[auto trainy]

And also I would check all my vacuum connections

[basscombat]

[quote=kaspr]Hi,

When I set the cruise, all functions work, except that it doesn't maintain a constant cruise speed. For example, if I set the cruise at 60, it will coast down to 58, and then accelerate up to 62, and then let up again so that it's just coasting back down to 58, and then over again.

if it happens on shallow hills mine was a sticky throttle/cruise cable...don't know which it was but lubing them cured the problem...ie when car slows down rpm such as downhill, when you begin going uphill only a small cable movment is required, if dirty the cable don't move.

[Vincenzo]

if you figure this out, please post. My cruise control doesn't engage. I'm thinking it might be something simple like a relay, but I have yet to find one marked cruise control.