cruise control

[eyezlee]

I've been browsing cruise control related threads now for a few days and am not finding anything along the lines of my problem... this may be a repost so pardon my ignorance—I consider my self a newbie to Benz’s but not to wrenching.

The car: 1985 190D 2.2 w/ auto

The problem: cruise will not work until after about 20 to 30 minutes of driving. After that, all functions work as expected at all speeds I've tried.

I've had this car for about 6 months and have slowly taking things off the "to fix" list. From the first day I drove this car the cruise has not worked. About 2 months ago I tried the cruise again and it kicked in but surged the throttle up and down. This made me think I had speedo cable issues but everything checks out and the speedo needle is stable also. Shortly after that I discovered a broken vacuum line…I repaired that hoping it may be the problem but it didn’t affect anything cruise related (It did fix a handful of other issues not surprisingly).

Last week I took the car out and noticed the cruise kicked in after about 30 minutes… I was shocked thinking that the throttle cable was stuck but after messing with the cruise stalk I discovered that everything was working as advertised. (It can’t get any better than a car that fixes it’s self.) Well it wasn’t to be: the same day I traveled back and discovered the cruise would not work right way but did kick in again after about 20 minutes.

The car is starting to gain my trust so I am taking it on more and more road trips but the cruise control oddity has me wondering WTF is happening…

Any feedback is welcome.