OK...I have looked through the boards and the only one that comes close to my problems, reply was check vacuum lines. Ok...i did that. Now what? I have a '83, Z28, 305, CC quad, no modifications. Worked at first (a year ago) then gradualy got harder to set. Would have to play with it. Now When I can set it, it searches for the speed droping 10 and increasing 10 mph. Last time I tried it, i hit the cruise and the accelerator went to the floor and did not come back. Figured I was at 110 mph before I gave up and canceled it with the brake. Looked for leaks and found a few but that not the problem. Linkage is free so it is not sticking. Module is not under the dash near passenger side firewall (just the computer) I can rebuild an engine but I cant get this damn cruise to work. Someone please help me...

 

I'd probably start out with a new switch.

 

Your 83 has a mechanical speedo and therefore has a speedo cable that goes into a Cruise Control Transducer that is located directly under the engine air intake scoop on the drivers side. (see pics). I haven't found many people on this board that know anything about them. I would suspect that it is this transducer that is failing. They don't last forever. You can take it into Napa, Advanced, or Autozone and get a new rebuilt one. They will want your old one for a core charge. I have also seen them on ebay for sale.

http://www.partsamerica.com/ProductD...pe=850&ptset=A

 

I've looked at umpteen gazillan third gens even of that vintage and never noticed that gaget. Cool yet frustrating sometimes when you think you've seen it all. GM made so many changes over the life span of the 3rd gen.

I bet that is the gaget causing you grief.

 

Doing some research after my first post, I found it is in fact a transducer. Olds and Vette have used the same transducer in the past. Being that it didnt work...i decided to take it apart and find out what makes it tick. Word to the unwise...Make carefull marks on the pieces being taken apart because they move and can be set with slots. I did however get the cruise to act on command now. Seems like the solenoid cover has a filter which has decentigrated and pieces went into the "whatever you call" in there. A little clean up and now comes on when it is supposed to. Has a 3 position plate where the cables go in and adjustible slot for the hold and enguage switch. OK...anyone got any ideas?

Geeves

PS Thanks for the info on the post.

 

I can't tell from your post, but did you fix it by cleaning it up? What is it not doing now?

 

I am playing around with it and the three hold adjustment made cruise cut out on brake but resume on brake release. But it did in fact start working. Went to the center hole and nothing but you can hear it click in. Moved the slide at the top and set at 35 and jumped to 80. will try this on the road rather than a jack.