I have looked and see nothing b\on hear like this. 1993 5.0 , 5 speedI did have a surging idle when I bought this car. That has been repaired for a good while now.
Problem that has just started. After driving for about 20 or 30 min. the idle goes up to close to 1800. I shut it off one time and it idled fine. Next time I shut it off and when cranked back up it was still idling at 1800. I did find the battery cable loose I mean very loose between the 2 above mention drives. I went ahead and dropped the power out to let the computer reset I asume. After reset It still idled high after about 30 min. Everything seems fine except this.
