I have an intermittent CC issue - I'll be cruising along fine, then all of a sudden the cruise will quit. Sometimes, just pressing resume is all it takes. Sometimes, nothing will activate it again including hitting the off button and then turning it back on or even turning the key off/on, although sometimes these efforts will correct it. On my FL trip recently, it would go hundreds of miles working flawlessly, other times it would shut off 2 miles after engaging it and not turn back on for an hour or so. I am thinking it could be a grounding issue, and here's why (and it seems strange): I noticed more than once that switching between the odo and trip meter would cause it to disengage, also when I turned on a map light a couple of times the cruise would quit. But it also would quit out of the blue with no prompting, and the above actions did not always cause a problem, not even 50% of the time. I had well over 5k miles of interstate driving on this trip, so I had a lot of time to try and replicate the issue, but nothing really points to one definitive answer.
Anyone have any suggestions?
On a completely different topic, now that I'm back in the high country, I notice a lot more smoke than when I was at sea level when I get on it. I could really get on it down there with just about no smoke, just a light haze unless I was being idiotic with the go pedal. Up here, I have to get into it gently until I build some revs/boost or I fog the whole neighborhood with diesel perfume. Just an air density difference?

 

Intermittent problems are a difficult to diagnose and repair. Sometimes you just have to wait until it fails to find the problem. A bad ground will sometimes create unusual electrical problems for more than one component, it is a possible cause.
I can't remember if the 94 had a driver side air bag... Does the air bag light ever flash? When your cruise fails, see if the horn will honk or not. If not you will need to remove the steering wheel and replace the clock spring. Vehicles with driver side air bags have a clock spring instead of slip rings between the wheel and column. If you do not have a driver side air bag, clean the slip rings.
Check the connector on the cruise servo for corrosion or melted pins. If the pins are melted then replace the servo and connector.

 

No driver's airbag as it's a F250 and the '94s didn't have them. I will check the servo and connections.

 

Check the throttle to servo cable, may have slack in it. Adjust as needed. A good way to check for dirty slip rings is to press and hold the on button and or the set button while turning the wheel slightly, lane change or similar. If the cruise engages then the slip rings could use a little cleaning. There is a special grease for slip rings I've only seen it at the dealer, not sure if it is still available. Any other issues with the speedo, RABS or OD lights? The speed sensor in the rear axle could be failing.

 

I'm pretty sure it is.
You can always turn down the pump a flat(which will, however, reduce high-RPM power), or get yourself an Aneroid for the pump to limit the fuel until you build boost(i.e. make it so you can just floor it and the fuel level builds with boost) -- Hypermax sells one for our trucks.

 

i am having the cruise control problem on my '94 f250 ...was told by a mechanic the servo needs replaced..pretty pricy new ...gonna check salvages...

 

as an added note to the cruise problem ...unrelated, but just wanted to say ...BEST truck i've ever owned,,,and i'm 70 years old, and have owned a lot of trucks...!! this is my first oil burner, and won't ever go back to gasoline...i've had this '94 turbo for about 10 years now, and have had to do absolutely NOTHING to it but tires, wiper blades, and fuel ...AWESOME TRUCK...!!!