Having a strange issue with my 1995 F-150 with a 5.0/automatic (overdrive). Truck has been sitting for three weeks in a very damp foggy area, start the truck and it goes up to a high idle and stays there, won't drop back down by tapping the gas pedal. I am also getting the check engine light coming on for a few seconds occasionally. Transmission is shifting a little late from 1st to 2nd, and it does not go into overdrive. Not sure where to go from here, any help or thoughts would be much appreciated.
Thanks,

 

Check throttle position sensor and idle air controler. The TPS can cause your trans to shift funny and mess with idle possibly. The IAC control air entering you TB to make a smooth idle.

 

Agreed but pull the error codes to see what they say.