cruise control out of control 85 carrera??

[captainlewis]

85 carrera cruise control. Was working fine, but last night went for a spin I turned on the cruise and nothing happened, about five minutes later it came on and started surging up and down heavy acceleration and deceleration. Turned it off tried again and it happened again, suggestions please, thank you JL

[schoward]

Sounds like your cruise control brain module is old and needs refurbishment. Do a search on how this is done or companies that can do this.

I had one that when cold outside would not work at all or engage and then a few mins later mash the gas pedal to the floor and not respond to the column stalk! Luckliy brake switch turned it off. Normal temps was fine. I've had two that were on the way out that did strange things like this, and have heard of others on this board with similar experiences. Most say re-solder all the joints on the circuit board (quite an easy task actually).

Do a search. Most of these CC modules have just not stood the test of time well, probably due to the early 80s electronics. Just not as durable as today's stuff.

[kodioneill]

search "cruise control solider" i took my ecu apart soldiered the joins on the pc board with a SMALL solider iron. make sure you use a low watt pencil type iron for this. used a magnifier and soldiered all the joins. works perfect cost $6.00.

[RSTarga]

cruise control on a 911 is an abomination just disconnect it. thats what your right foot is for.

[dfink]

I have a used control unit from a 1984 model. Don't know if it works but you pay shipping and we will figure out the price if it works.

[Mitch Leland]

While I'm sure your problem is in the module, I did make a big improvement on mine by changing out the vacuum lines and hose clamps. It now holds the speed a lot better. It might have been just loose hose clamps, but either way it's a cheap improvement if the module is good.