Stock1989 bronco II, Speed Control Surge

[broncogal]

Before i tear into it, i would like to get any tips, tricks, and advice for my Speed Contol Surge Problem. When at highway speed, and speed control is energized, i get a 2 to 3 hundred RPM up and down speed change. I can feel it in the gas pedal, and have tried it in both drive and overdrive with same results. I looked at the vacuum lines today and do not see any visual breaks or leaks.

Thanks, for any Ideas

 

[Uncle Gump]

The cruise servo will actually pull or release the throttle to compensate for uphill/downhill grades to keep mph steady. Would probably even pull some throttle in a good headwind. So some variation on throttle/rpm is normal.

 

[Uncle Gump]

I should add...

If you have a leaky CC vacuum servo... it will constantly "hunt" up and down in an attempt to find the correct RPM to maintain set speed.

 

[broncogal]

Ok I will take a close look at the servo in the morning, and find a test for it. Thanks for your input !!