wierd idle...

ok so i nocticed this today ...

when the car is in idle the rpms will drop from 1k to about 800 every 5 secs
its not a very rough idle but u can feel it , when it goes down and up again.

duno wut this could be
-im running on 3 new front plugs and 3 old back ones NKG
-i put in a fuel systems cleaner like 2 days ago into my current tank.

if that helps

probably dirty IAC. Do a search, you'll find plenty of threads. Normal idle should be a steady 700rpms. Also swap all 6 plugs, don't be lazy.

probably dirty IAC. Do a search, you'll find plenty of threads. Normal idle should be a steady 700rpms. Also swap all 6 plugs, don't be lazy.

i am i just didnt have the time this week cuz my step dad has all the tools...

normal idle 700rpms mines is more like 900 - 1k

Mine used to idle at about 900. Then my IAC went out. After I replaced it idles around 700 now...

how will u clean the IAC? pressurized air? is there like a guide thxs.

how will u clean the IAC? pressurized air? is there like a guide thxs.

here is a guide

http://stealth316.com/2-isc-iac.htm

1) Remove MAS
2) Get some electrical contact cleaner (wal-mart/autozone)
3) Spray away on the IAC/MAS electrical wire. Don't be afraid to spray 4 or 5 short bursts to drench it. Be sure to do both sides.
4) DO NOT touch the wire with ANYTHING! You will ruin your MAS.

Hope you have better luck than I did. If this doesn't fix the problem, you may need a new MAS.

ok so i check today and now my idle stays STILL right under the 1(not even 900)

but sometimes will go up

yea I have the exact same problem. Runs like sh** one day and runs great the next. I still haven't figured out what the problem is yet, but right now I would say it's your MAS.

so is it the MAS or the IAC?

I beleive their integrated circuits.

The MAS and IAC are completely different parts of the car.

I understand that but I guess I'm missing something. I keep hearing that the MAS and IAC on a 3000gt are combined. If they aren't then I would like the know where the IAC is.

I understand that but I guess I'm missing something. I keep hearing that the MAS and IAC on a 3000gt are combined. If they aren't then I would like the know where the IAC is.


Forget the MAS for the time being and focus on teh IAC. Check the link provided in post 6.

Alright I was confused. I read the post, went to my car and followed the removal steps. Althought I couldn't remove the entire thing (it's in the manifold pretty good.) I took out the 3 screws and just disassembled that peice. I cleaned it, took it for a drive... it ran like crap. This morning I started her up, and it ran great... so I dunno if this is the end to my problem (the CEL went away too). But yea, miami, listen to igovert and read the link on post 6 if you haven't already, because it may help you.

You can always check for a small vacum leak... (if it is a VR4)