My brono idles very oddly right when i start it up. The idle goes straight to 1200rpm for about 5 seconds, then up to 1500 for about 5 seconds, and then down again. It repeats this cycle until i rev the engine, at which point it rests at it's normal idle very steadily and then proceeds to drive great. Thanks for the help!

 

what year? i assume it has a carb in which case it is called the fast idle and kicking it down is normal. you can set the fast idle too.

 

Its actually a 93 bronco, no carb.

 

fuel pressure regulator. sits under the intake manifold area. shiny thing with a vacuum line attached to it.