Hello,
I believe all of my vacuum lines are intact (one more test on them tomorrow). How should I proceed with troubleshooting the cruise system, the pump or the computer?

1996 Disco I
115k

 

I would replace all of the lines before you try anything else. Vacuum line is not very expensive, and "looking ok" is not good enough. Have you pulled the pump out and looked at it? I think there is a little jumper hose on it, I had replaced all but that one, and it was bad too.

Just an FYI, you have to be going at least 28 MPH for the cruise to even think about engaging.

 

What's your problem with the cruise? Mind tends to accelerate slightly, then decellerate, and continue to do this throughout the trip. Is this your problem? Also, did you check the clearance on your cruise control throttle cable at the throttle body? There is a certain spec it should be set to, I can get it for you or it is in the RAVE manual.