P38 Idles high in the morning

[MikeD]

Just started yesterday.. and it happaned again today.. I walk out to my truck in the morning.. start it.. and instead of it revving to around 2k and then dropping instantly to 750rpm for the average idle.. it stays at 2k.. I let it sit for a few moments.. and no change.. i rev it.. and it returns to 2k.. After putting it into Reverse it stalls or just barely makes it and then drives fine from there.. Idles normally after a few minutes of driving..

any ideas? possible bad sensor? wtf? is it going to asplode??? :]

 

[Pugsly]

stepper motor?

 

[MikeD]

i hate it all.. thanks for the suggestion.. i haven't done anything as of yet.. need a few extra hours in the day heh

i plan on ripping apart the intake this evening and blowing out the MAF and cleaning the stepper motor.. i kind of thought the stepper motor only controlled a warm idle as the cold idle was all pre programmed.. but i could be wrong.. kind of makes me think its the alternator.. kind of weird tho because i don't have any other electrical problems

 

[sean]

i just posted when i saw this. i replaced the stepper motor with no improvement.

 

[MikeD]

same symptoms sean? sweet.. whats your next move?

i blew out all the sensors and shit and made sure everything was toight and clean last night.. no improvement.. going to pickup a new belt and do the alternator soon

 

[sean]

not sure yet. there has to be a sensor or something sticking/ giving the wrong reading. when i find it i'll let u know.

 

[agro1]

I had the same prob and it was a dirty stepper motor. Cleaned it with some steel wool and all was good.

 

[MikeD]

thanks guy.. i'll try cleaning that and see if it resolves the issue..

 

[sean]

i pulled out the k&n filter last night (and replaced with a stock one), cleaned the maf. idle was fine this morning.
i had replaced the stepper motor 1st and cleaned the maf with no luck.
so still not sure which it was maybe i didn't get all the crud out of the maf.there was no oil that i could tell had entered, it my k&n was very lightly oiled and i have been watching to make sure no oil was seeping up th intake.