Aerostar Cruise Control

[ehce]

just bought a '95 aerostar w/ 94,000 miles on it. The cruise control surges slightly when set above around 55 mph. Nothing big, it seems to hold speed fine, but is on/off throttle pretty often and less gradual than other vehicles I have driven. I have an '82 E-250, a '94 Civic and a '90 Aerostar that all operate more smoothly than this one.

I changed the cap & rotor, plugs & wires, and the air filter. I also cleaned the throttle body and mass flow sensor and disconnected the negative battery cable overnight to clear the CPU. all this led to a slight improvement but the problem is still there.

I used a code scanner and no problem codes came up.

Any ideas?

[coloradolove]

The '93 did that in the mountains, especially when you had to shift from overdrive to drive just to maintain speed up and down hills. I have no idea other than I learned to deal with it and then sold it to someone else and had it become their problem