Engine revs to 2700 or 2800 rpms when I start it up
I have a 2004 2.3 and it revs to 2700 or 2800 rpms when I first start it up. It revs when I start it up after work and at the end of the day too. Once it is warm it does not rev up when I start it up. The reving goes down after a few seconds. Sometimes when I start it the engine doesn't rev up enough so I have to barely hit the gas pedal and it immeditly revs up really high. I repalced the spark plugs and it didn't fix it. Next I will repalce the wires. The truck only has 47,000 miles on it.
Any ideas about how to stop the reving would be great.
2004 Ford Ranger, 2WD, 5 Speed, 2.3 4 cylinder, stock.