Idle issue

[apanello]

03 ford explorer 4.0

When idling under load in Drive, every once in a while the rpms drop quickly and then come right back to normal. What could be the cause? Is it a misfire? No codes.

 

[Hank102938]

I would check the IAC valve. It may momentarily be getting stuck or opening/closing too slowly causing your low rpms. Does it seem to do it after letting off the throttle and coming back down to idle?

 

[apanello]

Yep, it is random

 

[Hank102938]

If the IAC seems to be working properly, some other considerations may be a vacuum leak or a dirty/malfunctioning MAF sensor.

I'm guessing by your wording these dips only last a second or two?

 

[apanello]

Less than that