Rev on startup

[Kyle97-clipse]

Okay here's my problem when I start my car it revs toa about 2500. I think that this is a little high especially for a cold engine and I remeber that it didn't always use to do this. I was just wondering if anyone could point me in a direction to fix this here's what I got so far


No CELS for anything that would casue this I only have one because of the egr blockoff. I also did vacuum test and that was really good so no vacuum leaks either I'm stumped

 

[davidaham]

check you map sensor

 

[adamzty]

Like right after you start it up? Then it goes down to cold idle (~1100RPM) within a few seconds?

I think that's normal, mine did that.

 

[Kyle97-clipse]

Yeah it goes back down to normal idle

 

[urmomsaniceguy]

2nd adamzty. mine does that. MAP sensors wouldnt do it. it wouldnt start at all. i had to replace my MAP sensor.

 

[#40Fan]

Mine does the same thing, just not that high. Closer to 2k rpms. Only thing I haven't done is replace the IAC. If I had really thought that was the problem I would have replaced it a long time ago. I really do think it is the computer doing it.

 

[Bubbs Malone]

I have the same issue, sometimes it will rev higher than others.

 

[Griffeclipsed98]

my mom had a 97 plymyth neon espresso, brand spankin new back in the day and it had the neon 420a in it and it would do it as well my 420a in my 98 gs does it. one thing i do every once in awhile is remove my tb and take it all apart as far as removeing the tps and idle control and i clean everything and i also spray a small amount of very light weight grease on the idle control cylinoid and it helps a little bit to be more responsive. but it doesnt solve the high start up idle

but for the most part its a cold start safety feature in the ecu all it does is build oil pressure faster and it will not hurt your motor becouse on start up there is no load on the motor.

 

[rshissler]

mine does it as well and all the sensors are brand new and i have no vac leaks. Its just normal for these engines. My oil guage reads pressure as soon as the car starts so i dont worry about it.

 

[eddied118]

I had similar problems with my 96 gsx. It would idle fine when cold but when it got to operating temperature it would skyrocket to 2k rpm at idle... finally it threw a code p0505 (which is the Idle Air control). Replaced it and now the car idles perfect when cold and at operating temps..