Issue with Expy 1998 eb 5.4, low rpm

[isanchezgdl]

I have an issue with my expy 1998, when I start the engine (cold, first time on that day), it start at low rpm (400-500) but after a couple of mins it change to normal rpm, change from 400 to 650-700, this only happend once a day, only the first time I use it, and then if I turn off and turn on again it start at normal rpms, not low as the first time of the day. What could be?

 

[Bedrck47]

well being your in Mexico maybe it takes some time for it to wake up from a siesta.

clean your idle air control valve

 

[FordandPolaris]

If cleaning the IAC makes no difference, reset the PCM and let it idle for a little while. Should start at about 1000rpms and come down to 650ish after 5-10 seconds depending on the temperature.