1997 Grand Marquis - Cruise/Acceleration

No light or codes are present. I noticed the last few days that when the cruise control is initiallly engaged, the car starts to accelerate and then disengages. What I mean is, if the cruise is set at 60mph, it will accelerate to about 66-67mph and then the gas pedal will pop back and disengage. This also happened at various other speeds with an average increase of 5-7mph.

Today I noticed that the cruise sometimes won't even engage, even though the light on the dash indicates it is on. Other times it works fine. And still other times it will start accelerating when intially engaged.

About two-and-a-half years ago, Ford had a recall (05FS8) and they replaced the cruise deactivation switch underneath the master cylinder because it could possibly catch fire (The blue circled item in the picture). My apologies for the quality of the picture.

Any suggestions?

Btw, is the red circled item in the picture the PCM (Primary Control Module) or "brain"? Could this possibly have anything to do with this problem? Wouldn't a Ford scanner show if this item was defective? This was the suggestion of one of my Ford engineering buddies - but heck, what do they know, they just design them :sarcasmsign:.

I don't know about your problem, but what you have circled in your picture in red is the cruise control unit. There is a cable that extends out of it and all the way to the throttle body. This is what actually moves the throttle when you engage cruise control.