Cruise Control is accelerating and decelerating April 23, 2006, 03:43:02 AM well, i tried to find a thread about this and came up empty. my cruise DOES work, however it accelerates and decelerates while it's on.... for example, i set the cruise at 70, and it proceeds to let me go down to 68 and then races me to 72, says "oh i went too fast" and decelerates me back down to 68 then says "it...... too slow, i hope he doesn't notice so i'll speed up quick" so it's back up to 72 and so on and so forth.......anyway, it's not a fuse problem, so what would make a cruise control "oscilate" like that? Quote Selected
Cruise Control is accelerating and decelerating Reply #1 – April 23, 2006, 11:47:59 AM are you on level ground when its doing it? and is it a gradual type or real fast almost like passing gear and hitting the brakes type? Quote Selected
Cruise Control is accelerating and decelerating Reply #2 – April 23, 2006, 12:19:55 PM vacume leak maybe? Quote Selected
Cruise Control is accelerating and decelerating Reply #3 – April 23, 2006, 02:18:18 PM Quote from: Master_xzaviorare you on level ground when its doing it? and is it a gradual type or real fast almost like passing gear and hitting the brakes type?yeah, it does it regardless of the terrain and it speeds up fast enough to put me back in my seat a little..... but it doesn't downshift or anything.... when it decelerates it's like taking your foot off the gas..... it's almost as if it doesn't know how to hold the throttle stillQuote from: Tbird232civacume leak maybe?i thought it might be, but the lines up front look ok.... are there any vacuum lines from the cruise under the dash? Is there a way to test for leaks in the cruise system with the car sitting at idle? Quote Selected
Cruise Control is accelerating and decelerating Reply #4 – April 23, 2006, 06:21:57 PM Do you have an automatic parking break release? Is it hissing? That little vacum leak could screw with your whole vacume system. Other than that I couldn't say. Does the computer have anything to do with the cruise on EEC-III? Quote Selected
Cruise Control is accelerating and decelerating Reply #5 – April 23, 2006, 07:59:41 PM here's a pic from my evtsm...... no i do not have the park brake release and i don't hear a vacuum leak.... i have the digital dash and it did this BEFORE i added the tripminder...... however, does the fact that my tripminder isn't giving accurate instant mpg show that the cruise issue might be electrical..... my miles click off ok on the dash and the speed seems to be correct (other than the display doesn't hold the digital speed smooth either.... it's hard to keep it saying 55 even with the pedal)also, i have the cornering lights if that means anything Quote Selected
Cruise Control is accelerating and decelerating Reply #6 – April 23, 2006, 10:36:13 PM You may have a bad VSS if your speedo is acting up. Or a bad wire from the VSS. If the 83's with full digis had VSS's or cables? Quote Selected
Cruise Control is accelerating and decelerating Reply #7 – April 23, 2006, 11:04:40 PM i don't know what's on the tranny, but the back of the digital cluster has a speedo cable running to it.... way to go ford... digial guage with an buttstuffog input :)i wouldn't say it's acting up because it does show the right mph, but, having no frame of reference except my digital speedo in the van, it seems to fluxuate a whole bunch...... when you drive the van down the road and hold it at 50, the speedo stays at 50, but in the cougar, it goes 49, 51, 50, 49, 51, 50.... instead of staying put..... and that's WITHOUT the cruises help, just my lead footi think the signal goes from the tranny, to the speedo via the cable, then from the speedo to the cpu.... kinda of backasswards if you ask me..... Quote Selected
Cruise Control is accelerating and decelerating Reply #8 – April 25, 2006, 06:12:45 PM Your speedometer cable may be binding. Try pouring some graphite lub into it. Quote Selected
Cruise Control is accelerating and decelerating Reply #9 – April 25, 2006, 08:49:42 PM Also make sure the cruse controll cable is not binding. Quote Selected