Strange Idle Situation, anyone else have this issue???

[red90hatch]

Hey all,

I am fairly new to the forum but have searched thoroughly for any similar problems to mine, and no luck so far. I have a 1990 240sx with the original KA24E and it just recently decided to start acting up. I changed my rad today as well as adjusted my TPS closed voltage and now it wants to pick up and take off after idling for a few seconds. After driving and coming to a stop, the car will idle normally for a second and then gradually rev up to about 1900 rpm within a matter of 10 seconds. If I go for another quick drive and come to a stop, same thing. I would have thought vacuum leak, but like I said, it will idle fine for a few seconds and then its as though the ecm says "hey lets idle faster now". Maybe a IACV running out to full extension and not running back in? I know on GMs they run out then back in as a self test, do nissans do the same? Maybe to do with the adjustment I made to the TPS? Any suggestions are welcomed, thanks in advance!

[red90hatch]

C'mon guys, all those views and no one has seen anything like this before???

[TokayanaWayIsHome]

My 240 did that but only up to about 1700 RPM i adjusted spark plug gap and noticed the damn injectors could turn so i was dinkin' around with it and now my car has no idle problems

[gibald]

my car does that sometimes. ill be driving for a while and the car will be fully warmed up, but occaisonally ill pull up to a light or stop sign and my idle wont go down below 1500. that will continue for about 2 minutes and then all of a sudden ill be stopped and my idle will go down to normal. seems to only happen when i have the defroster on though. when its happening if i turn of the defroster it still wont make the idle go down though.