I haven't got anyone to respond to my original post so I thought I'd post in a different area. My son's 94 ext cab has been acting up lately. When he prepares to slow down and takes his foot completely off the gas pedal, the engine is giving a series of revs before returning to normal idle. (in gear) The tach is recognizing these revs as well. I changed the fuel filter a couple days ago, and my son said that it actually runs a little better, but is still acting up. Any input on what it might be or definetley is?