Originally Posted by paul1234
my Expedition will be drving down the road and suddenly just increase in speed like you've just floored it. Once I found the cruise control hung up and replaced it so that took care of that. it did it agian this weekend. Anyone have any ideas? I'm thinking that maybe it has to do with the charcoal canister purging to much. I've really got no clue and don't want to start thowring money at it. I've had it tuned up at the dealership and they repaired some burnt wiring. Thanks
First, get it scanned to check for codes, not all give a check engine light. Getting it scanned will report back what the system is thinking and may save alot of time.
Has it done it since the wires were repaired? Much of the devices in a car have 12V supplied continuously and they break the ground to turn it off, so a burnt wire may short a device to ground and turn it on, so to speak.
A purge canister purging excessively may cause a drop in vacuum, but it shouldn't carry enough fuel to run the engine at a noticeably higher speed, I would think.