Why does my cruise control surge?
Thread Starter
Team Owner
Joined: Nov 2000
Posts: 45,085
Likes: 1
From: I was a young troubadour when I rode in on a song, and I'll be an old troubadour when I'm gone.
St. Jude Donor '08
Why does my cruise control surge?
The cruse control on my '89 isn't quite right. When I set it at 45, the car surges to 46, then slows to 44 or 45, then surges ahead again, then back down and so on. The tack jumps all over the place. One second I'm getting 40 miles per gallon, and the next second only 15. Why won't my speed stay constant? Any ideas?
Drifting
Joined: Nov 2001
Posts: 1,783
Likes: 2
From: Latham NY
Re: Why does my cruise control surge? (X-FireChance)
There's a vacuum check valve coming off the back of the plenum with one line going to the cruise control and the other to the climate control system. It can stop working with heat and age. About $5 at any auto store.
