1993 E150 351w E4OD runs fine and cruise works well except on some long hills it will drop as much as 10 mph before downshifting and going back to set speed. Thanks for any help.

 

Make sure that the engine is tuned up and the transmission is in good condition maintenance-wise. Try the same thing without cruise control turned on. If the engine is in top shape and it continues to act up then look at the cruise control. You always want to start out with the basics.

 

Engine and trans both fine. works well off cruise. only happens with cruise on long hills

 

Hmm. Then I would check the servo for correct operation, check the throttle cable from the servo to the throttle body. Double check the kickdown if it is a linkage or a cable.